diff --git a/src/draw.rs b/src/draw.rs
index cfbbbf3..a26de36 100644
--- a/src/draw.rs
+++ b/src/draw.rs
@@ -11,7 +11,7 @@ use crate::{
         primitive::GetOtherJoint,
         seg::{LoneLooseSegWeight, SeqLooseSegWeight},
     },
-    layout::{Infringement, Layout, LayoutException},
+    layout::{rules::RulesTrait, Infringement, Layout, LayoutException},
     math::{Circle, NoTangents},
     rules::{Conditions, Rules},
     wraparoundable::WraparoundableIndex,
@@ -29,13 +29,13 @@ pub enum DrawException {
     CannotWrapAround(WraparoundableIndex, LayoutException, LayoutException),
 }
 
-pub struct Draw<'a> {
-    layout: &'a mut Layout,
+pub struct Draw<'a, R: RulesTrait> {
+    layout: &'a mut Layout<R>,
     rules: &'a Rules,
 }
 
-impl<'a> Draw<'a> {
-    pub fn new(layout: &'a mut Layout, rules: &'a Rules) -> Self {
+impl<'a, R: RulesTrait> Draw<'a, R> {
+    pub fn new(layout: &'a mut Layout<R>, rules: &'a Rules) -> Self {
         Self { layout, rules }
     }
 
@@ -95,6 +95,7 @@ impl<'a> Draw<'a> {
         head: Head,
         around: FixedDotIndex,
         width: f64,
+        offset: f64,
     ) -> Result<SegbendHead, DrawException> {
         let mut tangents = self.guide(&Default::default()).head_around_dot_segments(
             &head,
@@ -117,6 +118,7 @@ impl<'a> Draw<'a> {
                 tangent.start_point(),
                 tangent.end_point(),
                 dirs[i],
+                offset,
                 width,
             ) {
                 Ok(ok) => return Ok(ok),
@@ -138,6 +140,7 @@ impl<'a> Draw<'a> {
         head: Head,
         around: BendIndex,
         width: f64,
+        offset: f64,
     ) -> Result<SegbendHead, DrawException> {
         let mut tangents = self.guide(&Default::default()).head_around_bend_segments(
             &head,
@@ -160,6 +163,7 @@ impl<'a> Draw<'a> {
                 tangent.start_point(),
                 tangent.end_point(),
                 dirs[i],
+                offset,
                 width,
             ) {
                 Ok(ok) => return Ok(ok),
@@ -184,9 +188,10 @@ impl<'a> Draw<'a> {
         to: Point,
         cw: bool,
         width: f64,
+        offset: f64,
     ) -> Result<SegbendHead, LayoutException> {
         let head = self.extend_head(head, from)?;
-        self.segbend(head, around, to, cw, width)
+        self.segbend(head, around, to, cw, offset, width)
     }
 
     #[debug_ensures(self.layout.node_count() == old(self.layout.node_count()))]
@@ -208,6 +213,7 @@ impl<'a> Draw<'a> {
         to: Point,
         cw: bool,
         width: f64,
+        offset: f64,
     ) -> Result<SegbendHead, LayoutException> {
         let segbend = self.layout.insert_segbend(
             head.face(),
@@ -221,12 +227,12 @@ impl<'a> Draw<'a> {
             },
             SeqLooseSegWeight {
                 band: head.band(),
-                width: 3.0,
+                width,
             },
             LooseBendWeight {
                 band: head.band(),
-                width: 3.0,
-                offset: 3.0,
+                width,
+                offset,
                 cw,
             },
         )?;
@@ -250,7 +256,7 @@ impl<'a> Draw<'a> {
         Some(self.guide(&Default::default()).head(prev_dot, band))
     }
 
-    fn guide(&'a self, conditions: &'a Conditions) -> Guide {
-        Guide::new(self.layout, self.rules, conditions)
+    fn guide(&'a self, conditions: &'a Conditions) -> Guide<R> {
+        Guide::new(self.layout, conditions)
     }
 }
diff --git a/src/layout/band.rs b/src/layout/band.rs
index bff0bca..fcabed9 100644
--- a/src/layout/band.rs
+++ b/src/layout/band.rs
@@ -11,13 +11,15 @@ use crate::{
     },
 };
 
-pub struct Band<'a> {
+use super::rules::RulesTrait;
+
+pub struct Band<'a, R: RulesTrait> {
     pub index: BandIndex,
-    layout: &'a Layout,
+    layout: &'a Layout<R>,
 }
 
-impl<'a> Band<'a> {
-    pub fn new(index: BandIndex, layout: &'a Layout) -> Self {
+impl<'a, R: RulesTrait> Band<'a, R> {
+    pub fn new(index: BandIndex, layout: &'a Layout<R>) -> Self {
         Self { index, layout }
     }
 
@@ -85,7 +87,7 @@ impl<'a> Band<'a> {
     }
 }
 
-impl<'a> GetNet for Band<'a> {
+impl<'a, R: RulesTrait> GetNet for Band<'a, R> {
     fn net(&self) -> i64 {
         self.weight().net
     }
diff --git a/src/layout/bend.rs b/src/layout/bend.rs
index 75b6c48..d0298e7 100644
--- a/src/layout/bend.rs
+++ b/src/layout/bend.rs
@@ -10,6 +10,7 @@ use crate::{
             MakePrimitive, Retag,
         },
         primitive::{GenericPrimitive, Primitive},
+        rules::RulesTrait,
         Layout,
     },
 };
diff --git a/src/layout/dot.rs b/src/layout/dot.rs
index 27ef41b..c673c03 100644
--- a/src/layout/dot.rs
+++ b/src/layout/dot.rs
@@ -13,6 +13,7 @@ use crate::{
             MakePrimitive, Retag,
         },
         primitive::{GenericPrimitive, Primitive},
+        rules::RulesTrait,
         Layout,
     },
     math::Circle,
diff --git a/src/layout/graph.rs b/src/layout/graph.rs
index 9b63e70..b58439b 100644
--- a/src/layout/graph.rs
+++ b/src/layout/graph.rs
@@ -14,6 +14,7 @@ use super::{
     bend::{FixedBendIndex, FixedBendWeight, LooseBendIndex, LooseBendWeight},
     dot::{FixedDotIndex, FixedDotWeight, LooseDotIndex, LooseDotWeight},
     primitive::Primitive,
+    rules::RulesTrait,
     seg::{
         FixedSegIndex, FixedSegWeight, LoneLooseSegIndex, LoneLooseSegWeight, SeqLooseSegIndex,
         SeqLooseSegWeight,
@@ -40,7 +41,7 @@ pub trait GetBandIndex {
 
 #[enum_dispatch]
 pub trait MakePrimitive {
-    fn primitive<'a>(&self, layout: &'a Layout) -> Primitive<'a>;
+    fn primitive<'a, R: RulesTrait>(&self, layout: &'a Layout<R>) -> Primitive<'a, R>;
 }
 
 macro_rules! impl_weight {
@@ -54,7 +55,7 @@ macro_rules! impl_weight {
         pub type $index_struct = GenericIndex<$weight_struct>;
 
         impl MakePrimitive for $index_struct {
-            fn primitive<'a>(&self, layout: &'a Layout) -> Primitive<'a> {
+            fn primitive<'a, R: RulesTrait>(&self, layout: &'a Layout<R>) -> Primitive<'a, R> {
                 Primitive::$weight_variant(GenericPrimitive::new(*self, layout))
             }
         }
diff --git a/src/layout/guide.rs b/src/layout/guide.rs
index 77168cd..b57708b 100644
--- a/src/layout/guide.rs
+++ b/src/layout/guide.rs
@@ -15,7 +15,7 @@ use crate::{
     rules::{Conditions, Rules},
 };
 
-use super::segbend::Segbend;
+use super::{rules::RulesTrait, segbend::Segbend};
 
 #[enum_dispatch]
 pub trait HeadTrait {
@@ -63,19 +63,14 @@ impl HeadTrait for SegbendHead {
     }
 }
 
-pub struct Guide<'a, 'b> {
-    layout: &'a Layout,
-    rules: &'a Rules,
+pub struct Guide<'a, 'b, R: RulesTrait> {
+    layout: &'a Layout<R>,
     conditions: &'b Conditions,
 }
 
-impl<'a, 'b> Guide<'a, 'b> {
-    pub fn new(layout: &'a Layout, rules: &'a Rules, conditions: &'b Conditions) -> Self {
-        Self {
-            layout,
-            rules,
-            conditions,
-        }
+impl<'a, 'b, R: RulesTrait> Guide<'a, 'b, R> {
+    pub fn new(layout: &'a Layout<R>, conditions: &'b Conditions) -> Self {
+        Self { layout, conditions }
     }
 
     pub fn head_into_dot_segment(
diff --git a/src/layout/layout.rs b/src/layout/layout.rs
index 65efe93..5b4d8e9 100644
--- a/src/layout/layout.rs
+++ b/src/layout/layout.rs
@@ -14,6 +14,7 @@ use super::connectivity::{
 };
 use super::geometry::with_rtree::GeometryWithRtree;
 use super::loose::{GetNextLoose, Loose, LooseIndex};
+use super::rules::RulesTrait;
 use super::segbend::Segbend;
 use crate::graph::{GenericIndex, GetNodeIndex};
 use crate::layout::bend::BendIndex;
@@ -28,8 +29,7 @@ use crate::layout::{
     geometry::shape::{Shape, ShapeTrait},
     graph::{GeometryIndex, GeometryWeight, GetComponentIndex, MakePrimitive},
     primitive::{
-        GenericPrimitive, GetConnectable, GetCore, GetInnerOuter, GetJoints, GetOtherJoint,
-        GetWeight, MakeShape,
+        GenericPrimitive, GetCore, GetInnerOuter, GetJoints, GetOtherJoint, GetWeight, MakeShape,
     },
     seg::{
         FixedSegIndex, FixedSegWeight, LoneLooseSegIndex, LoneLooseSegWeight, SegIndex,
@@ -69,8 +69,7 @@ pub struct Collision(pub Shape, pub GeometryIndex);
 pub struct AlreadyConnected(pub i64, pub GeometryIndex);
 
 #[derive(Debug)]
-pub struct Layout {
-    connectivity: ConnectivityGraph,
+pub struct Layout<R: RulesTrait> {
     geometry_with_rtree: GeometryWithRtree<
         GeometryWeight,
         DotWeight,
@@ -81,13 +80,16 @@ pub struct Layout {
         SegIndex,
         BendIndex,
     >,
+    connectivity: ConnectivityGraph,
+    rules: R,
 }
 
-impl Layout {
-    pub fn new() -> Self {
-        Layout {
-            connectivity: StableDiGraph::default(),
+impl<R: RulesTrait> Layout<R> {
+    pub fn new(rules: R) -> Self {
+        Self {
             geometry_with_rtree: GeometryWithRtree::new(),
+            connectivity: StableDiGraph::default(),
+            rules,
         }
     }
 
@@ -411,9 +413,8 @@ impl Layout {
             let cw = primitive.weight().cw;
             let ends = primitive.joints();
 
-            let rules = Default::default();
             let conditions = Default::default();
-            let guide = Guide::new(self, &rules, &conditions);
+            let guide = Guide::new(self, &conditions);
 
             let from_head = guide.rear_head(ends.1);
             let to_head = guide.rear_head(ends.0);
@@ -717,10 +718,6 @@ impl Layout {
         self.geometry_with_rtree.flip_bend(bend.into());
     }
 
-    /*pub fn bow(&self, bend: LooseBendIndex) -> Bow {
-        Bow::from_bend(bend, &self.graph)
-    }*/
-
     pub fn segbend(&self, dot: LooseDotIndex) -> Segbend {
         Segbend::from_dot(dot, self)
     }
@@ -769,7 +766,7 @@ impl Layout {
     }
 }
 
-impl Layout {
+impl<R: RulesTrait> Layout<R> {
     #[debug_ensures(self.geometry_with_rtree.graph().node_count() == old(self.geometry_with_rtree.graph().node_count()))]
     #[debug_ensures(self.geometry_with_rtree.graph().edge_count() == old(self.geometry_with_rtree.graph().edge_count()))]
     pub fn move_dot(&mut self, dot: DotIndex, to: Point) -> Result<(), Infringement> {
@@ -815,10 +812,7 @@ impl Layout {
         self.geometry_with_rtree
             .rtree()
             .locate_in_envelope_intersecting(&RTreeObject::envelope(&shape))
-            .filter(|wrapper| {
-                let other_index = wrapper.data;
-                !node.primitive(self).connectable(other_index)
-            })
+            .filter(|wrapper| !self.are_connectable(node, wrapper.data))
             .filter(|wrapper| !except.contains(&wrapper.data))
             .filter(|wrapper| shape.intersects(wrapper.geom()))
             .map(|wrapper| wrapper.data)
@@ -835,18 +829,24 @@ impl Layout {
         self.geometry_with_rtree
             .rtree()
             .locate_in_envelope_intersecting(&RTreeObject::envelope(&shape))
-            .filter(|wrapper| {
-                let other_index = wrapper.data;
-                !node.primitive(self).connectable(other_index)
-            })
+            .filter(|wrapper| !self.are_connectable(node, wrapper.data))
             .filter(|wrapper| shape.intersects(wrapper.geom()))
             .map(|wrapper| wrapper.data)
             .next()
             .and_then(|collidee| Some(Collision(shape, collidee)))
     }
+
+    #[debug_ensures(self.geometry_with_rtree.graph().node_count() == old(self.geometry_with_rtree.graph().node_count()))]
+    #[debug_ensures(self.geometry_with_rtree.graph().edge_count() == old(self.geometry_with_rtree.graph().edge_count()))]
+    fn are_connectable(&self, node1: GeometryIndex, node2: GeometryIndex) -> bool {
+        let node1_net = node1.primitive(self).net();
+        let node2_net = node2.primitive(self).net();
+
+        (node1_net == node2_net) || node1_net == -1 || node2_net == -2
+    }
 }
 
-impl Layout {
+impl<R: RulesTrait> Layout<R> {
     #[debug_ensures(self.geometry_with_rtree.graph().node_count() == old(self.geometry_with_rtree.graph().node_count()))]
     #[debug_ensures(self.geometry_with_rtree.graph().edge_count() == old(self.geometry_with_rtree.graph().edge_count()))]
     pub fn connectivity(&self) -> &ConnectivityGraph {
@@ -872,25 +872,31 @@ impl Layout {
 
     #[debug_ensures(self.geometry_with_rtree.graph().node_count() == old(self.geometry_with_rtree.graph().node_count()))]
     #[debug_ensures(self.geometry_with_rtree.graph().edge_count() == old(self.geometry_with_rtree.graph().edge_count()))]
-    pub fn primitive<W>(&self, index: GenericIndex<W>) -> GenericPrimitive<W> {
+    pub fn rules(&self) -> &R {
+        &self.rules
+    }
+
+    #[debug_ensures(self.geometry_with_rtree.graph().node_count() == old(self.geometry_with_rtree.graph().node_count()))]
+    #[debug_ensures(self.geometry_with_rtree.graph().edge_count() == old(self.geometry_with_rtree.graph().edge_count()))]
+    pub fn primitive<W>(&self, index: GenericIndex<W>) -> GenericPrimitive<W, R> {
         GenericPrimitive::new(index, self)
     }
 
     #[debug_ensures(self.geometry_with_rtree.graph().node_count() == old(self.geometry_with_rtree.graph().node_count()))]
     #[debug_ensures(self.geometry_with_rtree.graph().edge_count() == old(self.geometry_with_rtree.graph().edge_count()))]
-    pub fn wraparoundable(&self, index: WraparoundableIndex) -> Wraparoundable {
+    pub fn wraparoundable(&self, index: WraparoundableIndex) -> Wraparoundable<R> {
         Wraparoundable::new(index, self)
     }
 
     #[debug_ensures(self.geometry_with_rtree.graph().node_count() == old(self.geometry_with_rtree.graph().node_count()))]
     #[debug_ensures(self.geometry_with_rtree.graph().edge_count() == old(self.geometry_with_rtree.graph().edge_count()))]
-    pub fn loose(&self, index: LooseIndex) -> Loose {
+    pub fn loose(&self, index: LooseIndex) -> Loose<R> {
         Loose::new(index, self)
     }
 
     #[debug_ensures(self.geometry_with_rtree.graph().node_count() == old(self.geometry_with_rtree.graph().node_count()))]
     #[debug_ensures(self.geometry_with_rtree.graph().edge_count() == old(self.geometry_with_rtree.graph().edge_count()))]
-    pub fn band(&self, index: BandIndex) -> Band {
+    pub fn band(&self, index: BandIndex) -> Band<R> {
         Band::new(index, self)
     }
 }
diff --git a/src/layout/loose.rs b/src/layout/loose.rs
index bd8f684..623adad 100644
--- a/src/layout/loose.rs
+++ b/src/layout/loose.rs
@@ -13,6 +13,8 @@ use crate::{
     },
 };
 
+use super::rules::RulesTrait;
+
 #[enum_dispatch]
 pub trait GetNextLoose {
     fn next_loose(&self, maybe_prev: Option<LooseIndex>) -> Option<LooseIndex>;
@@ -39,15 +41,15 @@ impl From<LooseIndex> for GeometryIndex {
 }
 
 #[enum_dispatch(GetNextLoose, GetLayout, GetNodeIndex)]
-pub enum Loose<'a> {
-    Dot(LooseDot<'a>),
-    LoneSeg(LoneLooseSeg<'a>),
-    SeqSeg(SeqLooseSeg<'a>),
-    Bend(LooseBend<'a>),
+pub enum Loose<'a, R: RulesTrait> {
+    Dot(LooseDot<'a, R>),
+    LoneSeg(LoneLooseSeg<'a, R>),
+    SeqSeg(SeqLooseSeg<'a, R>),
+    Bend(LooseBend<'a, R>),
 }
 
-impl<'a> Loose<'a> {
-    pub fn new(index: LooseIndex, layout: &'a Layout) -> Self {
+impl<'a, R: RulesTrait> Loose<'a, R> {
+    pub fn new(index: LooseIndex, layout: &'a Layout<R>) -> Self {
         match index {
             LooseIndex::Dot(dot) => layout.primitive(dot).into(),
             LooseIndex::LoneSeg(seg) => layout.primitive(seg).into(),
@@ -57,7 +59,7 @@ impl<'a> Loose<'a> {
     }
 }
 
-impl<'a> GetNextLoose for LooseDot<'a> {
+impl<'a, R: RulesTrait> GetNextLoose for LooseDot<'a, R> {
     fn next_loose(&self, maybe_prev: Option<LooseIndex>) -> Option<LooseIndex> {
         let bend = self.bend();
         let Some(prev) = maybe_prev else {
@@ -72,13 +74,13 @@ impl<'a> GetNextLoose for LooseDot<'a> {
     }
 }
 
-impl<'a> GetNextLoose for LoneLooseSeg<'a> {
+impl<'a, R: RulesTrait> GetNextLoose for LoneLooseSeg<'a, R> {
     fn next_loose(&self, _maybe_prev: Option<LooseIndex>) -> Option<LooseIndex> {
         None
     }
 }
 
-impl<'a> GetNextLoose for SeqLooseSeg<'a> {
+impl<'a, R: RulesTrait> GetNextLoose for SeqLooseSeg<'a, R> {
     fn next_loose(&self, maybe_prev: Option<LooseIndex>) -> Option<LooseIndex> {
         let ends = self.joints();
         let Some(prev) = maybe_prev else {
@@ -96,7 +98,7 @@ impl<'a> GetNextLoose for SeqLooseSeg<'a> {
     }
 }
 
-impl<'a> GetNextLoose for LooseBend<'a> {
+impl<'a, R: RulesTrait> GetNextLoose for LooseBend<'a, R> {
     fn next_loose(&self, maybe_prev: Option<LooseIndex>) -> Option<LooseIndex> {
         let ends = self.joints();
         let Some(prev) = maybe_prev else {
diff --git a/src/layout/mod.rs b/src/layout/mod.rs
index c960acc..f8d1766 100644
--- a/src/layout/mod.rs
+++ b/src/layout/mod.rs
@@ -9,6 +9,7 @@ pub mod guide;
 mod layout;
 pub mod loose;
 pub mod primitive;
+pub mod rules;
 pub mod seg;
 pub mod segbend;
 
diff --git a/src/layout/primitive.rs b/src/layout/primitive.rs
index 4d6a319..347a70a 100644
--- a/src/layout/primitive.rs
+++ b/src/layout/primitive.rs
@@ -20,19 +20,11 @@ use crate::layout::{
     Layout,
 };
 
-#[enum_dispatch]
-pub trait GetLayout {
-    fn layout(&self) -> &Layout;
-}
+use super::rules::RulesTrait;
 
 #[enum_dispatch]
-pub trait GetConnectable: GetNet + GetLayout {
-    fn connectable(&self, node: GeometryIndex) -> bool {
-        let this = self.net();
-        let other = node.primitive(self.layout()).net();
-
-        (this == other) || this == -1 || other == -1
-    }
+pub trait GetLayout<'a, R: RulesTrait> {
+    fn layout(&self) -> &Layout<R>;
 }
 
 #[enum_dispatch]
@@ -82,7 +74,7 @@ pub trait GetJoints<F, T> {
     fn joints(&self) -> (F, T);
 }
 
-pub trait GetFirstRail: GetLayout + GetNodeIndex {
+pub trait GetFirstRail<'a, R: RulesTrait>: GetLayout<'a, R> + GetNodeIndex {
     fn first_rail(&self) -> Option<LooseBendIndex> {
         self.layout()
             .geometry()
@@ -95,7 +87,7 @@ pub trait GetBendIndex {
     fn bend_index(&self) -> BendIndex;
 }
 
-pub trait GetCore: GetLayout + GetBendIndex {
+pub trait GetCore<'a, R: RulesTrait>: GetLayout<'a, R> + GetBendIndex {
     fn core(&self) -> FixedDotIndex {
         FixedDotIndex::new(
             self.layout()
@@ -106,7 +98,7 @@ pub trait GetCore: GetLayout + GetBendIndex {
     }
 }
 
-pub trait GetInnerOuter: GetLayout + GetBendIndex {
+pub trait GetInnerOuter<'a, R: RulesTrait>: GetLayout<'a, R> + GetBendIndex {
     fn inner(&self) -> Option<LooseBendIndex> {
         self.layout()
             .geometry()
@@ -124,7 +116,7 @@ pub trait GetInnerOuter: GetLayout + GetBendIndex {
 
 macro_rules! impl_primitive {
     ($primitive_struct:ident, $weight_struct:ident) => {
-        impl<'a> GetWeight<$weight_struct> for $primitive_struct<'a> {
+        impl<'a, R: RulesTrait> GetWeight<$weight_struct> for $primitive_struct<'a, R> {
             fn weight(&self) -> $weight_struct {
                 if let GeometryWeight::$primitive_struct(weight) = self.tagged_weight() {
                     weight
@@ -140,13 +132,13 @@ macro_rules! impl_fixed_primitive {
     ($primitive_struct:ident, $weight_struct:ident) => {
         impl_primitive!($primitive_struct, $weight_struct);
 
-        impl<'a> GetComponentIndex for $primitive_struct<'a> {
+        impl<'a, R: RulesTrait> GetComponentIndex for $primitive_struct<'a, R> {
             fn component(&self) -> ComponentIndex {
                 self.weight().component()
             }
         }
 
-        impl<'a> GetNet for $primitive_struct<'a> {
+        impl<'a, R: RulesTrait> GetNet for $primitive_struct<'a, R> {
             fn net(&self) -> i64 {
                 self.layout()
                     .connectivity()
@@ -162,7 +154,7 @@ macro_rules! impl_loose_primitive {
     ($primitive_struct:ident, $weight_struct:ident) => {
         impl_primitive!($primitive_struct, $weight_struct);
 
-        impl<'a> GetNet for $primitive_struct<'a> {
+        impl<'a, R: RulesTrait> GetNet for $primitive_struct<'a, R> {
             fn net(&self) -> i64 {
                 self.layout()
                     .connectivity()
@@ -174,25 +166,25 @@ macro_rules! impl_loose_primitive {
     };
 }
 
-#[enum_dispatch(GetNet, GetWidth, GetLayout, GetConnectable, MakeShape, GetLimbs)]
-pub enum Primitive<'a> {
-    FixedDot(FixedDot<'a>),
-    LooseDot(LooseDot<'a>),
-    FixedSeg(FixedSeg<'a>),
-    LoneLooseSeg(LoneLooseSeg<'a>),
-    SeqLooseSeg(SeqLooseSeg<'a>),
-    FixedBend(FixedBend<'a>),
-    LooseBend(LooseBend<'a>),
+#[enum_dispatch(GetNet, GetWidth, GetLayout, MakeShape, GetLimbs)]
+pub enum Primitive<'a, R: RulesTrait> {
+    FixedDot(FixedDot<'a, R>),
+    LooseDot(LooseDot<'a, R>),
+    FixedSeg(FixedSeg<'a, R>),
+    LoneLooseSeg(LoneLooseSeg<'a, R>),
+    SeqLooseSeg(SeqLooseSeg<'a, R>),
+    FixedBend(FixedBend<'a, R>),
+    LooseBend(LooseBend<'a, R>),
 }
 
 #[derive(Debug)]
-pub struct GenericPrimitive<'a, W> {
+pub struct GenericPrimitive<'a, W, R: RulesTrait> {
     pub index: GenericIndex<W>,
-    layout: &'a Layout,
+    layout: &'a Layout<R>,
 }
 
-impl<'a, W> GenericPrimitive<'a, W> {
-    pub fn new(index: GenericIndex<W>, layout: &'a Layout) -> Self {
+impl<'a, W, R: RulesTrait> GenericPrimitive<'a, W, R> {
+    pub fn new(index: GenericIndex<W>, layout: &'a Layout<R>) -> Self {
         Self { index, layout }
     }
 
@@ -205,44 +197,42 @@ impl<'a, W> GenericPrimitive<'a, W> {
             .unwrap()
     }
 
-    fn primitive<WW>(&self, index: GenericIndex<WW>) -> GenericPrimitive<WW> {
+    fn primitive<WW>(&self, index: GenericIndex<WW>) -> GenericPrimitive<WW, R> {
         GenericPrimitive::new(index, &self.layout)
     }
 }
 
-impl<'a, W> GetInterior<GeometryIndex> for GenericPrimitive<'a, W> {
+impl<'a, W, R: RulesTrait> GetInterior<GeometryIndex> for GenericPrimitive<'a, W, R> {
     fn interior(&self) -> Vec<GeometryIndex> {
         vec![self.tagged_weight().retag(self.index.node_index())]
     }
 }
 
-impl<'a, W> GetLayout for GenericPrimitive<'a, W> {
-    fn layout(&self) -> &Layout {
+impl<'a, W, R: RulesTrait> GetLayout<'a, R> for GenericPrimitive<'a, W, R> {
+    fn layout(&self) -> &Layout<R> {
         self.layout
     }
 }
 
-impl<'a, W> GetNodeIndex for GenericPrimitive<'a, W> {
+impl<'a, W, R: RulesTrait> GetNodeIndex for GenericPrimitive<'a, W, R> {
     fn node_index(&self) -> NodeIndex<usize> {
         self.index.node_index()
     }
 }
 
-impl<'a, W> GetConnectable for GenericPrimitive<'a, W> where GenericPrimitive<'a, W>: GetNet {}
-
-impl<'a, W: GetWidth> GetWidth for GenericPrimitive<'a, W>
+impl<'a, W: GetWidth, R: RulesTrait> GetWidth for GenericPrimitive<'a, W, R>
 where
-    GenericPrimitive<'a, W>: GetWeight<W>,
+    GenericPrimitive<'a, W, R>: GetWeight<W>,
 {
     fn width(&self) -> f64 {
         self.weight().width()
     }
 }
 
-pub type FixedDot<'a> = GenericPrimitive<'a, FixedDotWeight>;
+pub type FixedDot<'a, R> = GenericPrimitive<'a, FixedDotWeight, R>;
 impl_fixed_primitive!(FixedDot, FixedDotWeight);
 
-impl<'a> FixedDot<'a> {
+impl<'a, R: RulesTrait> FixedDot<'a, R> {
     pub fn first_loose(&self, _band: BandIndex) -> Option<LooseIndex> {
         self.layout
             .geometry()
@@ -266,13 +256,13 @@ impl<'a> FixedDot<'a> {
     }
 }
 
-impl<'a> MakeShape for FixedDot<'a> {
+impl<'a, R: RulesTrait> MakeShape for FixedDot<'a, R> {
     fn shape(&self) -> Shape {
         self.layout.geometry().dot_shape(self.index.into())
     }
 }
 
-impl<'a> GetLimbs for FixedDot<'a> {
+impl<'a, R: RulesTrait> GetLimbs for FixedDot<'a, R> {
     fn segs(&self) -> Vec<SegIndex> {
         self.layout
             .geometry()
@@ -288,12 +278,12 @@ impl<'a> GetLimbs for FixedDot<'a> {
     }
 }
 
-impl<'a> GetFirstRail for FixedDot<'a> {}
+impl<'a, R: RulesTrait> GetFirstRail<'a, R> for FixedDot<'a, R> {}
 
-pub type LooseDot<'a> = GenericPrimitive<'a, LooseDotWeight>;
+pub type LooseDot<'a, R> = GenericPrimitive<'a, LooseDotWeight, R>;
 impl_loose_primitive!(LooseDot, LooseDotWeight);
 
-impl<'a> LooseDot<'a> {
+impl<'a, R: RulesTrait> LooseDot<'a, R> {
     pub fn seg(&self) -> Option<SeqLooseSegIndex> {
         self.layout
             .geometry()
@@ -312,13 +302,13 @@ impl<'a> LooseDot<'a> {
     }
 }
 
-impl<'a> MakeShape for LooseDot<'a> {
+impl<'a, R: RulesTrait> MakeShape for LooseDot<'a, R> {
     fn shape(&self) -> Shape {
         self.layout.geometry().dot_shape(self.index.into())
     }
 }
 
-impl<'a> GetLimbs for LooseDot<'a> {
+impl<'a, R: RulesTrait> GetLimbs for LooseDot<'a, R> {
     fn segs(&self) -> Vec<SegIndex> {
         if let Some(seg) = self.seg() {
             vec![seg.into()]
@@ -332,18 +322,18 @@ impl<'a> GetLimbs for LooseDot<'a> {
     }
 }
 
-pub type FixedSeg<'a> = GenericPrimitive<'a, FixedSegWeight>;
+pub type FixedSeg<'a, R> = GenericPrimitive<'a, FixedSegWeight, R>;
 impl_fixed_primitive!(FixedSeg, FixedSegWeight);
 
-impl<'a> MakeShape for FixedSeg<'a> {
+impl<'a, R: RulesTrait> MakeShape for FixedSeg<'a, R> {
     fn shape(&self) -> Shape {
         self.layout.geometry().seg_shape(self.index.into())
     }
 }
 
-impl<'a> GetLimbs for FixedSeg<'a> {}
+impl<'a, R: RulesTrait> GetLimbs for FixedSeg<'a, R> {}
 
-impl<'a> GetJoints<FixedDotIndex, FixedDotIndex> for FixedSeg<'a> {
+impl<'a, R: RulesTrait> GetJoints<FixedDotIndex, FixedDotIndex> for FixedSeg<'a, R> {
     fn joints(&self) -> (FixedDotIndex, FixedDotIndex) {
         let (from, to) = self.layout.geometry().seg_joints(self.index.into());
         (
@@ -353,20 +343,20 @@ impl<'a> GetJoints<FixedDotIndex, FixedDotIndex> for FixedSeg<'a> {
     }
 }
 
-impl<'a> GetOtherJoint<FixedDotIndex, FixedDotIndex> for FixedSeg<'a> {}
+impl<'a, R: RulesTrait> GetOtherJoint<FixedDotIndex, FixedDotIndex> for FixedSeg<'a, R> {}
 
-pub type LoneLooseSeg<'a> = GenericPrimitive<'a, LoneLooseSegWeight>;
+pub type LoneLooseSeg<'a, R> = GenericPrimitive<'a, LoneLooseSegWeight, R>;
 impl_loose_primitive!(LoneLooseSeg, LoneLooseSegWeight);
 
-impl<'a> MakeShape for LoneLooseSeg<'a> {
+impl<'a, R: RulesTrait> MakeShape for LoneLooseSeg<'a, R> {
     fn shape(&self) -> Shape {
         self.layout.geometry().seg_shape(self.index.into())
     }
 }
 
-impl<'a> GetLimbs for LoneLooseSeg<'a> {}
+impl<'a, R: RulesTrait> GetLimbs for LoneLooseSeg<'a, R> {}
 
-impl<'a> GetJoints<FixedDotIndex, FixedDotIndex> for LoneLooseSeg<'a> {
+impl<'a, R: RulesTrait> GetJoints<FixedDotIndex, FixedDotIndex> for LoneLooseSeg<'a, R> {
     fn joints(&self) -> (FixedDotIndex, FixedDotIndex) {
         let (from, to) = self.layout.geometry().seg_joints(self.index.into());
         (
@@ -376,20 +366,20 @@ impl<'a> GetJoints<FixedDotIndex, FixedDotIndex> for LoneLooseSeg<'a> {
     }
 }
 
-impl<'a> GetOtherJoint<FixedDotIndex, FixedDotIndex> for LoneLooseSeg<'a> {}
+impl<'a, R: RulesTrait> GetOtherJoint<FixedDotIndex, FixedDotIndex> for LoneLooseSeg<'a, R> {}
 
-pub type SeqLooseSeg<'a> = GenericPrimitive<'a, SeqLooseSegWeight>;
+pub type SeqLooseSeg<'a, R> = GenericPrimitive<'a, SeqLooseSegWeight, R>;
 impl_loose_primitive!(SeqLooseSeg, SeqLooseSegWeight);
 
-impl<'a> MakeShape for SeqLooseSeg<'a> {
+impl<'a, R: RulesTrait> MakeShape for SeqLooseSeg<'a, R> {
     fn shape(&self) -> Shape {
         self.layout.geometry().seg_shape(self.index.into())
     }
 }
 
-impl<'a> GetLimbs for SeqLooseSeg<'a> {}
+impl<'a, R: RulesTrait> GetLimbs for SeqLooseSeg<'a, R> {}
 
-impl<'a> GetJoints<DotIndex, LooseDotIndex> for SeqLooseSeg<'a> {
+impl<'a, R: RulesTrait> GetJoints<DotIndex, LooseDotIndex> for SeqLooseSeg<'a, R> {
     fn joints(&self) -> (DotIndex, LooseDotIndex) {
         let joints = self.layout.geometry().seg_joints(self.index.into());
         if let DotWeight::Fixed(..) = self.layout.geometry().dot_weight(joints.0) {
@@ -411,26 +401,26 @@ impl<'a> GetJoints<DotIndex, LooseDotIndex> for SeqLooseSeg<'a> {
     }
 }
 
-impl<'a> GetOtherJoint<DotIndex, LooseDotIndex> for SeqLooseSeg<'a> {}
+impl<'a, R: RulesTrait> GetOtherJoint<DotIndex, LooseDotIndex> for SeqLooseSeg<'a, R> {}
 
-pub type FixedBend<'a> = GenericPrimitive<'a, FixedBendWeight>;
+pub type FixedBend<'a, R> = GenericPrimitive<'a, FixedBendWeight, R>;
 impl_fixed_primitive!(FixedBend, FixedBendWeight);
 
-impl<'a> GetBendIndex for FixedBend<'a> {
+impl<'a, R: RulesTrait> GetBendIndex for FixedBend<'a, R> {
     fn bend_index(&self) -> BendIndex {
         self.index.into()
     }
 }
 
-impl<'a> MakeShape for FixedBend<'a> {
+impl<'a, R: RulesTrait> MakeShape for FixedBend<'a, R> {
     fn shape(&self) -> Shape {
         self.layout.geometry().bend_shape(self.index.into())
     }
 }
 
-impl<'a> GetLimbs for FixedBend<'a> {}
+impl<'a, R: RulesTrait> GetLimbs for FixedBend<'a, R> {}
 
-impl<'a> GetJoints<FixedDotIndex, FixedDotIndex> for FixedBend<'a> {
+impl<'a, R: RulesTrait> GetJoints<FixedDotIndex, FixedDotIndex> for FixedBend<'a, R> {
     fn joints(&self) -> (FixedDotIndex, FixedDotIndex) {
         let (from, to) = self.layout.geometry().bend_joints(self.index.into());
         (
@@ -440,41 +430,41 @@ impl<'a> GetJoints<FixedDotIndex, FixedDotIndex> for FixedBend<'a> {
     }
 }
 
-impl<'a> GetOtherJoint<FixedDotIndex, FixedDotIndex> for FixedBend<'a> {}
-impl<'a> GetFirstRail for FixedBend<'a> {}
-impl<'a> GetCore for FixedBend<'a> {} // TODO: Fixed bends don't have cores actually.
-                                      //impl<'a> GetInnerOuter for FixedBend<'a> {}
+impl<'a, R: RulesTrait> GetOtherJoint<FixedDotIndex, FixedDotIndex> for FixedBend<'a, R> {}
+impl<'a, R: RulesTrait> GetFirstRail<'a, R> for FixedBend<'a, R> {}
+impl<'a, R: RulesTrait> GetCore<'a, R> for FixedBend<'a, R> {} // TODO: Fixed bends don't have cores actually.
+                                                               //impl<'a, R: QueryRules> GetInnerOuter for FixedBend<'a, R> {}
 
-pub type LooseBend<'a> = GenericPrimitive<'a, LooseBendWeight>;
+pub type LooseBend<'a, R> = GenericPrimitive<'a, LooseBendWeight, R>;
 impl_loose_primitive!(LooseBend, LooseBendWeight);
 
-impl<'a> GetBendIndex for LooseBend<'a> {
+impl<'a, R: RulesTrait> GetBendIndex for LooseBend<'a, R> {
     fn bend_index(&self) -> BendIndex {
         self.index.into()
     }
 }
 
-impl<'a> From<LooseBend<'a>> for BendIndex {
-    fn from(bend: LooseBend<'a>) -> BendIndex {
+impl<'a, R: RulesTrait> From<LooseBend<'a, R>> for BendIndex {
+    fn from(bend: LooseBend<'a, R>) -> BendIndex {
         bend.index.into()
     }
 }
 
-impl<'a> MakeShape for LooseBend<'a> {
+impl<'a, R: RulesTrait> MakeShape for LooseBend<'a, R> {
     fn shape(&self) -> Shape {
         self.layout.geometry().bend_shape(self.index.into())
     }
 }
 
-impl<'a> GetLimbs for LooseBend<'a> {}
+impl<'a, R: RulesTrait> GetLimbs for LooseBend<'a, R> {}
 
-impl<'a> GetOffset for LooseBend<'a> {
+impl<'a, R: RulesTrait> GetOffset for LooseBend<'a, R> {
     fn offset(&self) -> f64 {
         self.weight().offset
     }
 }
 
-impl<'a> GetJoints<LooseDotIndex, LooseDotIndex> for LooseBend<'a> {
+impl<'a, R: RulesTrait> GetJoints<LooseDotIndex, LooseDotIndex> for LooseBend<'a, R> {
     fn joints(&self) -> (LooseDotIndex, LooseDotIndex) {
         let (from, to) = self.layout.geometry().bend_joints(self.index.into());
         (
@@ -484,6 +474,6 @@ impl<'a> GetJoints<LooseDotIndex, LooseDotIndex> for LooseBend<'a> {
     }
 }
 
-impl<'a> GetOtherJoint<LooseDotIndex, LooseDotIndex> for LooseBend<'a> {}
-impl<'a> GetCore for LooseBend<'a> {}
-impl<'a> GetInnerOuter for LooseBend<'a> {}
+impl<'a, R: RulesTrait> GetOtherJoint<LooseDotIndex, LooseDotIndex> for LooseBend<'a, R> {}
+impl<'a, R: RulesTrait> GetCore<'a, R> for LooseBend<'a, R> {}
+impl<'a, R: RulesTrait> GetInnerOuter<'a, R> for LooseBend<'a, R> {}
diff --git a/src/layout/rules.rs b/src/layout/rules.rs
new file mode 100644
index 0000000..0f27f97
--- /dev/null
+++ b/src/layout/rules.rs
@@ -0,0 +1,18 @@
+pub struct Conditions {
+    layer: Option<String>,
+    region: Option<String>,
+    netclass: Option<String>,
+}
+
+pub struct LayerNetclassConditions {
+    region: Option<String>,
+}
+
+pub trait RulesTrait {
+    fn clearance(conditions1: &Conditions, conditions2: &Conditions) -> f64;
+    fn clearance_limit(
+        layer: String,
+        netclass: String,
+        conditions: &LayerNetclassConditions,
+    ) -> f64;
+}
diff --git a/src/layout/seg.rs b/src/layout/seg.rs
index 5eccfac..afc1bd3 100644
--- a/src/layout/seg.rs
+++ b/src/layout/seg.rs
@@ -10,6 +10,7 @@ use crate::{
             MakePrimitive, Retag,
         },
         primitive::{GenericPrimitive, Primitive},
+        rules::RulesTrait,
         Layout,
     },
 };
diff --git a/src/layout/segbend.rs b/src/layout/segbend.rs
index 817b297..9beda1c 100644
--- a/src/layout/segbend.rs
+++ b/src/layout/segbend.rs
@@ -7,6 +7,8 @@ use crate::layout::{
     Layout,
 };
 
+use super::rules::RulesTrait;
+
 #[derive(Debug, Clone, Copy)]
 pub struct Segbend {
     pub seg: SeqLooseSegIndex,
@@ -15,7 +17,7 @@ pub struct Segbend {
 }
 
 impl Segbend {
-    pub fn from_dot(dot: LooseDotIndex, layout: &Layout) -> Self {
+    pub fn from_dot(dot: LooseDotIndex, layout: &Layout<impl RulesTrait>) -> Self {
         let bend = LooseDot::new(dot, layout).bend();
         let dot = LooseBend::new(bend, layout).other_joint(dot);
         let seg = LooseDot::new(dot, layout).seg().unwrap();
diff --git a/src/main.rs b/src/main.rs
index 8b4895c..69f3f1a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -28,11 +28,12 @@ use layout::dot::FixedDotWeight;
 use layout::geometry::shape::{Shape, ShapeTrait};
 use layout::graph::{GeometryIndex, MakePrimitive};
 use layout::primitive::MakeShape;
+use layout::rules::{Conditions, LayerNetclassConditions, RulesTrait};
 use layout::seg::FixedSegWeight;
 use layout::{Infringement, Layout, LayoutException};
 use mesh::{Mesh, MeshEdgeReference, VertexIndex};
 use petgraph::visit::{EdgeRef, IntoEdgeReferences};
-use router::RouterObserver;
+use router::RouterObserverTrait;
 
 use sdl2::event::Event;
 use sdl2::keyboard::Keycode;
@@ -57,26 +58,42 @@ use tracer::{Trace, Tracer};
 use crate::math::Circle;
 use crate::router::Router;
 
+struct ConstantClearance {}
+
+impl RulesTrait for ConstantClearance {
+    fn clearance(conditions1: &Conditions, conditions2: &Conditions) -> f64 {
+        3.0
+    }
+
+    fn clearance_limit(
+        layer: String,
+        netclass: String,
+        conditions: &LayerNetclassConditions,
+    ) -> f64 {
+        3.0
+    }
+}
+
 // Clunky enum to work around borrow checker.
-enum RouterOrLayout<'a> {
-    Router(&'a mut Router),
-    Layout(&'a Layout),
+enum RouterOrLayout<'a, R: RulesTrait> {
+    Router(&'a mut Router<R>),
+    Layout(&'a Layout<R>),
 }
 
 struct EmptyRouterObserver;
 
-impl RouterObserver for EmptyRouterObserver {
-    fn on_rework(&mut self, _tracer: &Tracer, _trace: &Trace) {}
-    fn before_probe(&mut self, _tracer: &Tracer, _trace: &Trace, _edge: MeshEdgeReference) {}
+impl<R: RulesTrait> RouterObserverTrait<R> for EmptyRouterObserver {
+    fn on_rework(&mut self, _tracer: &Tracer<R>, _trace: &Trace) {}
+    fn before_probe(&mut self, _tracer: &Tracer<R>, _trace: &Trace, _edge: MeshEdgeReference) {}
     fn on_probe(
         &mut self,
-        _tracer: &Tracer,
+        _tracer: &Tracer<R>,
         _trace: &Trace,
         _edge: MeshEdgeReference,
         _result: Result<(), DrawException>,
     ) {
     }
-    fn on_estimate(&mut self, _tracer: &Tracer, _vertex: VertexIndex) {}
+    fn on_estimate(&mut self, _tracer: &Tracer<R>, _vertex: VertexIndex) {}
 }
 
 struct DebugRouterObserver<'a> {
@@ -102,8 +119,8 @@ impl<'a> DebugRouterObserver<'a> {
     }
 }
 
-impl<'a> RouterObserver for DebugRouterObserver<'a> {
-    fn on_rework(&mut self, tracer: &Tracer, trace: &Trace) {
+impl<'a, R: RulesTrait> RouterObserverTrait<R> for DebugRouterObserver<'a> {
+    fn on_rework(&mut self, tracer: &Tracer<R>, trace: &Trace) {
         render_times(
             self.event_pump,
             self.window,
@@ -119,7 +136,7 @@ impl<'a> RouterObserver for DebugRouterObserver<'a> {
         );
     }
 
-    fn before_probe(&mut self, tracer: &Tracer, trace: &Trace, edge: MeshEdgeReference) {
+    fn before_probe(&mut self, tracer: &Tracer<R>, trace: &Trace, edge: MeshEdgeReference) {
         let mut path = trace.path.clone();
         path.push(edge.target());
         render_times(
@@ -139,7 +156,7 @@ impl<'a> RouterObserver for DebugRouterObserver<'a> {
 
     fn on_probe(
         &mut self,
-        tracer: &Tracer,
+        tracer: &Tracer<R>,
         trace: &Trace,
         _edge: MeshEdgeReference,
         result: Result<(), DrawException>,
@@ -168,7 +185,7 @@ impl<'a> RouterObserver for DebugRouterObserver<'a> {
         );
     }
 
-    fn on_estimate(&mut self, _tracer: &Tracer, _vertex: VertexIndex) {}
+    fn on_estimate(&mut self, _tracer: &Tracer<R>, _vertex: VertexIndex) {}
 }
 
 fn main() -> Result<(), anyhow::Error> {
@@ -218,7 +235,7 @@ fn main() -> Result<(), anyhow::Error> {
 
     let mut event_pump = sdl_context.event_pump().unwrap();
     let _i = 0;
-    let mut router = Router::new();
+    let mut router = Router::new(ConstantClearance {});
 
     let component1_1 = router.layout.add_component(1);
     let component1_2 = router.layout.add_component(1);
@@ -321,7 +338,7 @@ fn main() -> Result<(), anyhow::Error> {
         dot2_1,
         FixedSegWeight {
             component: component2,
-            width: 16.0,
+            width: 3.0,
         },
     );
 
@@ -341,7 +358,7 @@ fn main() -> Result<(), anyhow::Error> {
         dot2_2,
         FixedSegWeight {
             component: component2,
-            width: 16.0,
+            width: 3.0,
         },
     );
 
@@ -372,7 +389,7 @@ fn main() -> Result<(), anyhow::Error> {
         dot4,
         FixedSegWeight {
             component: component2,
-            width: 16.0,
+            width: 3.0,
         },
     );
 
@@ -392,7 +409,7 @@ fn main() -> Result<(), anyhow::Error> {
         dot5,
         FixedSegWeight {
             component: component2,
-            width: 16.0,
+            width: 3.0,
         },
     );
 
@@ -412,7 +429,7 @@ fn main() -> Result<(), anyhow::Error> {
         dot1_2,
         FixedSegWeight {
             component: component2,
-            width: 16.0,
+            width: 3.0,
         },
     );
 
@@ -421,7 +438,7 @@ fn main() -> Result<(), anyhow::Error> {
         dot2_2,
         FixedSegWeight {
             component: component2,
-            width: 16.0,
+            width: 3.0,
         },
     );
 
@@ -441,7 +458,7 @@ fn main() -> Result<(), anyhow::Error> {
         dot6,
         FixedSegWeight {
             component: component2,
-            width: 16.0,
+            width: 3.0,
         },
     );
 
@@ -461,7 +478,7 @@ fn main() -> Result<(), anyhow::Error> {
         dot7,
         FixedSegWeight {
             net: 20,
-            width: 16.0,
+            width: 3.0,
         },
     );*/
 
@@ -613,7 +630,7 @@ fn render_times(
     window: &Window,
     renderer: &mut Renderer<GLDevice>,
     font_context: &CanvasFontContext,
-    mut router_or_layout: RouterOrLayout,
+    mut router_or_layout: RouterOrLayout<impl RulesTrait>,
     maybe_band: Option<BandIndex>,
     mut maybe_mesh: Option<Mesh>,
     path: &[VertexIndex],
diff --git a/src/mesh.rs b/src/mesh.rs
index acd5198..6383112 100644
--- a/src/mesh.rs
+++ b/src/mesh.rs
@@ -7,6 +7,7 @@ use petgraph::visit::{self, NodeIndexable};
 use petgraph::{stable_graph::NodeIndex, visit::EdgeRef};
 use spade::{HasPosition, InsertionError, Point2};
 
+use crate::layout::rules::RulesTrait;
 use crate::triangulation::TriangulationEdgeReference;
 use crate::{
     graph::GetNodeIndex,
@@ -82,7 +83,7 @@ pub struct Mesh {
 }
 
 impl Mesh {
-    pub fn new(layout: &Layout) -> Self {
+    pub fn new(layout: &Layout<impl RulesTrait>) -> Self {
         let mut this = Self {
             triangulation: Triangulation::new(layout),
             vertex_to_triangulation_vertex: Vec::new(),
@@ -92,7 +93,7 @@ impl Mesh {
         this
     }
 
-    pub fn generate(&mut self, layout: &Layout) -> Result<(), InsertionError> {
+    pub fn generate(&mut self, layout: &Layout<impl RulesTrait>) -> Result<(), InsertionError> {
         for node in layout.nodes() {
             let center = node.primitive(layout).shape().center();
 
diff --git a/src/router.rs b/src/router.rs
index 3efa4b4..42d901e 100644
--- a/src/router.rs
+++ b/src/router.rs
@@ -7,6 +7,7 @@ use thiserror::Error;
 use crate::astar::{astar, AstarStrategy, PathTracker};
 use crate::draw::DrawException;
 use crate::layout::guide::HeadTrait;
+use crate::layout::rules::RulesTrait;
 use crate::layout::Layout;
 use crate::layout::{
     connectivity::BandIndex,
@@ -39,33 +40,38 @@ pub enum RoutingErrorKind {
     AStar,
 }
 
-pub trait RouterObserver {
-    fn on_rework(&mut self, tracer: &Tracer, trace: &Trace);
-    fn before_probe(&mut self, tracer: &Tracer, trace: &Trace, edge: MeshEdgeReference);
+pub trait RouterObserverTrait<R: RulesTrait> {
+    fn on_rework(&mut self, tracer: &Tracer<R>, trace: &Trace);
+    fn before_probe(&mut self, tracer: &Tracer<R>, trace: &Trace, edge: MeshEdgeReference);
     fn on_probe(
         &mut self,
-        tracer: &Tracer,
+        tracer: &Tracer<R>,
         trace: &Trace,
         edge: MeshEdgeReference,
         result: Result<(), DrawException>,
     );
-    fn on_estimate(&mut self, tracer: &Tracer, vertex: VertexIndex);
+    fn on_estimate(&mut self, tracer: &Tracer<R>, vertex: VertexIndex);
 }
 
-pub struct Router {
-    pub layout: Layout,
+pub struct Router<R: RulesTrait> {
+    pub layout: Layout<R>,
     rules: Rules,
 }
 
-struct RouterAstarStrategy<'a, RO: RouterObserver> {
-    tracer: Tracer<'a>,
+struct RouterAstarStrategy<'a, RO: RouterObserverTrait<R>, R: RulesTrait> {
+    tracer: Tracer<'a, R>,
     trace: Trace,
     to: FixedDotIndex,
     observer: &'a mut RO,
 }
 
-impl<'a, RO: RouterObserver> RouterAstarStrategy<'a, RO> {
-    pub fn new(tracer: Tracer<'a>, trace: Trace, to: FixedDotIndex, observer: &'a mut RO) -> Self {
+impl<'a, RO: RouterObserverTrait<R>, R: RulesTrait> RouterAstarStrategy<'a, RO, R> {
+    pub fn new(
+        tracer: Tracer<'a, R>,
+        trace: Trace,
+        to: FixedDotIndex,
+        observer: &'a mut RO,
+    ) -> Self {
         Self {
             tracer,
             trace,
@@ -75,7 +81,9 @@ impl<'a, RO: RouterObserver> RouterAstarStrategy<'a, RO> {
     }
 }
 
-impl<'a, RO: RouterObserver> AstarStrategy<&Mesh, f64> for RouterAstarStrategy<'a, RO> {
+impl<'a, RO: RouterObserverTrait<R>, R: RulesTrait> AstarStrategy<&Mesh, f64>
+    for RouterAstarStrategy<'a, RO, R>
+{
     fn is_goal(&mut self, vertex: VertexIndex, tracker: &PathTracker<&Mesh>) -> bool {
         let new_path = tracker.reconstruct_path_to(vertex);
 
@@ -120,10 +128,10 @@ impl<'a, RO: RouterObserver> AstarStrategy<&Mesh, f64> for RouterAstarStrategy<'
     }
 }
 
-impl Router {
-    pub fn new() -> Self {
+impl<R: RulesTrait> Router<R> {
+    pub fn new(rules: R) -> Self {
         Router {
-            layout: Layout::new(),
+            layout: Layout::new(rules),
             rules: Rules::new(),
         }
     }
@@ -132,7 +140,7 @@ impl Router {
         &mut self,
         from: FixedDotIndex,
         to: FixedDotIndex,
-        observer: &mut impl RouterObserver,
+        observer: &mut impl RouterObserverTrait<R>,
     ) -> Result<BandIndex, RoutingError> {
         // XXX: Should we actually store the mesh? May be useful for debugging, but doesn't look
         // right.
@@ -166,7 +174,7 @@ impl Router {
         &mut self,
         band: BandIndex,
         to: Point,
-        observer: &mut impl RouterObserver,
+        observer: &mut impl RouterObserverTrait<R>,
     ) -> Result<BandIndex, RoutingError> {
         let from_dot = self.layout.band(band).from();
         let to_dot = self.layout.band(band).to().unwrap();
@@ -175,7 +183,7 @@ impl Router {
         self.route_band(from_dot, to_dot, observer)
     }
 
-    pub fn tracer<'a>(&'a mut self, mesh: &'a Mesh) -> Tracer {
+    pub fn tracer<'a>(&'a mut self, mesh: &'a Mesh) -> Tracer<R> {
         Tracer::new(&mut self.layout, &self.rules, mesh)
     }
 }
diff --git a/src/tracer.rs b/src/tracer.rs
index f09007f..e0ba5d4 100644
--- a/src/tracer.rs
+++ b/src/tracer.rs
@@ -6,6 +6,7 @@ use crate::{
         bend::LooseBendIndex,
         dot::FixedDotIndex,
         guide::{BareHead, Head, SegbendHead},
+        rules::RulesTrait,
         Layout,
     },
     mesh::{Mesh, VertexIndex},
@@ -18,14 +19,14 @@ pub struct Trace {
     pub head: Head,
 }
 
-pub struct Tracer<'a> {
-    pub layout: &'a mut Layout,
+pub struct Tracer<'a, R: RulesTrait> {
+    pub layout: &'a mut Layout<R>,
     pub rules: &'a Rules,
     pub mesh: &'a Mesh,
 }
 
-impl<'a> Tracer<'a> {
-    pub fn new(layout: &'a mut Layout, rules: &'a Rules, mesh: &'a Mesh) -> Self {
+impl<'a, R: RulesTrait> Tracer<'a, R> {
+    pub fn new(layout: &'a mut Layout<R>, rules: &'a Rules, mesh: &'a Mesh) -> Self {
         Tracer {
             layout,
             rules,
@@ -128,7 +129,9 @@ impl<'a> Tracer<'a> {
         around: FixedDotIndex,
         width: f64,
     ) -> Result<SegbendHead, DrawException> {
-        let head = self.draw().segbend_around_dot(head, around.into(), width)?;
+        let head = self
+            .draw()
+            .segbend_around_dot(head, around.into(), width, 3.0)?;
         Ok(head)
     }
 
@@ -140,7 +143,7 @@ impl<'a> Tracer<'a> {
     ) -> Result<SegbendHead, DrawException> {
         let head = self
             .draw()
-            .segbend_around_bend(head, around.into(), width)?;
+            .segbend_around_bend(head, around.into(), width, 3.0)?;
 
         Ok(head)
     }
@@ -156,7 +159,7 @@ impl<'a> Tracer<'a> {
         trace.path.pop();
     }
 
-    fn draw(&mut self) -> Draw {
+    fn draw(&mut self) -> Draw<R> {
         Draw::new(&mut self.layout, &self.rules)
     }
 }
diff --git a/src/triangulation.rs b/src/triangulation.rs
index 5bd710b..79d7dba 100644
--- a/src/triangulation.rs
+++ b/src/triangulation.rs
@@ -4,7 +4,10 @@ use geo::{point, Point};
 use petgraph::visit::{self, NodeIndexable};
 use spade::{handles::FixedVertexHandle, DelaunayTriangulation, HasPosition, InsertionError};
 
-use crate::{graph::GetNodeIndex, layout::Layout};
+use crate::{
+    graph::GetNodeIndex,
+    layout::{rules::RulesTrait, Layout},
+};
 
 pub trait GetVertexIndex<I> {
     fn vertex(&self) -> I;
@@ -20,7 +23,7 @@ pub struct Triangulation<I: Copy + PartialEq + GetNodeIndex, W: GetVertexIndex<I
 impl<I: Copy + PartialEq + GetNodeIndex, W: GetVertexIndex<I> + HasPosition<Scalar = f64>>
     Triangulation<I, W>
 {
-    pub fn new(layout: &Layout) -> Self {
+    pub fn new(layout: &Layout<impl RulesTrait>) -> Self {
         let mut this = Self {
             triangulation: <DelaunayTriangulation<W> as spade::Triangulation>::new(),
             vertex_to_handle: Vec::new(),
diff --git a/src/wraparoundable.rs b/src/wraparoundable.rs
index 5c5bdf2..0d8668a 100644
--- a/src/wraparoundable.rs
+++ b/src/wraparoundable.rs
@@ -10,12 +10,13 @@ use crate::{
         primitive::{
             FixedBend, FixedDot, GetFirstRail, GetInnerOuter, GetLayout, LooseBend, Primitive,
         },
+        rules::RulesTrait,
         Layout,
     },
 };
 
 #[enum_dispatch]
-pub trait GetWraparound: GetLayout + GetNodeIndex {
+pub trait GetWraparound: GetNodeIndex {
     fn wraparound(&self) -> Option<LooseBendIndex>;
 }
 
@@ -47,14 +48,14 @@ impl From<BendIndex> for WraparoundableIndex {
 }
 
 #[enum_dispatch(GetWraparound, GetLayout, GetNodeIndex)]
-pub enum Wraparoundable<'a> {
-    FixedDot(FixedDot<'a>),
-    FixedBend(FixedBend<'a>),
-    LooseBend(LooseBend<'a>),
+pub enum Wraparoundable<'a, R: RulesTrait> {
+    FixedDot(FixedDot<'a, R>),
+    FixedBend(FixedBend<'a, R>),
+    LooseBend(LooseBend<'a, R>),
 }
 
-impl<'a> Wraparoundable<'a> {
-    pub fn new(index: WraparoundableIndex, layout: &'a Layout) -> Self {
+impl<'a, R: RulesTrait> Wraparoundable<'a, R> {
+    pub fn new(index: WraparoundableIndex, layout: &'a Layout<R>) -> Self {
         match index {
             WraparoundableIndex::FixedDot(dot) => layout.primitive(dot).into(),
             WraparoundableIndex::FixedBend(bend) => layout.primitive(bend).into(),
@@ -63,19 +64,19 @@ impl<'a> Wraparoundable<'a> {
     }
 }
 
-impl<'a> GetWraparound for FixedDot<'a> {
+impl<'a, R: RulesTrait> GetWraparound for FixedDot<'a, R> {
     fn wraparound(&self) -> Option<LooseBendIndex> {
         self.first_rail()
     }
 }
 
-impl<'a> GetWraparound for LooseBend<'a> {
+impl<'a, R: RulesTrait> GetWraparound for LooseBend<'a, R> {
     fn wraparound(&self) -> Option<LooseBendIndex> {
         self.outer()
     }
 }
 
-impl<'a> GetWraparound for FixedBend<'a> {
+impl<'a, R: RulesTrait> GetWraparound for FixedBend<'a, R> {
     fn wraparound(&self) -> Option<LooseBendIndex> {
         self.first_rail()
     }