Tangent Map — Milwaukee Lakefront Half
40 cuttable bends · built from half_marathon.gpx · road names from OSM
How the number is built. Cutting a bend of angle θ on a line 3 m inside the centerline saves 3·θ metres. Summed over every bend of 15° or more: 124 m theoretical, trimmed to 115 m after capping the two U-turns (you round a cone, you don't cut through it). That's 33 sec at 7:40/mi — if you hit every one. In a field, with cones and aid stations, half to two-thirds of it is the honest expectation: 18–25 sec. Against a locked 1:40:30 with zero stop budget, that is the entire cushion.
The Whole Course
North is up. Start bottom-left (Wisconsin Ave), north to Newberry, back south down Lincoln Memorial, over the Hoan Bridge to the Lake Parkway turnaround at 10.37, back north, finish bottom-right. Numbers are mile marks.
Three-quarters of the gain is in the first 5.2 miles. Miles 8.1–9.8 and 11.0–12.6 are the bridge deck — dead straight, nothing to win, no reason to think about position. Everything worth executing is over before the second climb starts.
Zone by Zone
A · Downtown & the Prospect climb Wisconsin Ave → Prospect Ave
| Mile | Bend | Run | Where | Saves |
|---|---|---|---|---|
| 0.21 | 17° | RIGHT | East Wisconsin Avenue | 0.9 m |
| 0.25 | 21° | LEFT | East Wisconsin Avenue | 1.1 m |
| 0.73–0.78 | 82° | LEFT | East Wisconsin Avenue | 4.3 m |
| 0.89 | 17° | LEFT | North Prospect Avenue | 0.9 m |
| 0.98 | 59° | RIGHT | North Prospect Avenue | 3.1 m |
| 1.05–1.12 | 74° | LEFT | North Prospect Avenue | 3.8 m |
| 1.13–1.27 | 69° | RIGHT | North Prospect Avenue | 3.6 m |
Zone total: 18 m ≈ 5 sec.
B · The East Side grid Lafayette · Terrace · Wahl · Lake Dr · Newberry
| Mile | Bend | Run | Where | Saves |
|---|---|---|---|---|
| 2.12 | 90° | RIGHT | East Lafayette Place | 4.7 m |
| 2.17–2.36 | 89° | LEFT | East Lafayette Place | 4.6 m |
| 2.75 | 83° | RIGHT | North Terrace Avenue | 4.4 m |
| 2.76–2.86 | 88° | LEFT | North Wahl Avenue | 4.6 m |
| 3.14–3.36 | 92° | LEFT | North Terrace Avenue | 4.8 m |
| 3.37 | 80° | RIGHT | North Lake Drive | 4.2 m |
| 3.38–3.50 | 114° | LEFT | North Lake Drive | 6.0 m |
| 3.71 | 180° | RIGHT | East Newberry Boulevard | 5.0 m |
| 3.93–4.04 | 86° | LEFT | North Lake Drive | 4.5 m |
| 4.28 | 18° | RIGHT | North Lake Drive | 0.9 m |
| 4.28 | 17° | LEFT | East Kenwood Boulevard | 0.9 m |
| 4.30 | 105° | RIGHT | North Lincoln Memorial Drive | 5.5 m |
Zone total: 50 m ≈ 14 sec.
C · Lincoln Memorial Drive the long lakefront sweepers
| Mile | Bend | Run | Where | Saves |
|---|---|---|---|---|
| 4.28 | 18° | RIGHT | North Lake Drive | 0.9 m |
| 4.28 | 17° | LEFT | East Kenwood Boulevard | 0.9 m |
| 4.30 | 105° | RIGHT | North Lincoln Memorial Drive | 5.5 m |
| 4.41–4.46 | 46° | RIGHT | North Lincoln Memorial Drive | 2.4 m |
| 4.46 | 22° | LEFT | North Lincoln Memorial Drive | 1.2 m |
| 4.48–4.74 | 76° | RIGHT | North Lincoln Memorial Drive | 4.0 m |
| 4.92–5.14 | 55° | RIGHT | North Lincoln Memorial Drive | 2.9 m |
| 5.42–5.63 | 24° | LEFT | North Lincoln Memorial Drive | 1.2 m |
| 5.73–5.84 | 25° | RIGHT | North Lincoln Memorial Drive | 1.3 m |
| 6.11–6.27 | 43° | RIGHT | North Lincoln Memorial Drive | 2.3 m |
| 6.30–6.72 | 53° | LEFT | North Lincoln Memorial Drive | 2.8 m |
| 7.24 | 20° | RIGHT | North Lincoln Memorial Drive | 1.0 m |
| 7.29–7.49 | 45° | LEFT | North Lincoln Memorial Drive | 2.4 m |
| 7.55 | 22° | RIGHT | North Lincoln Memorial Drive | 1.2 m |
| 7.73 | 23° | LEFT | East Clybourn Street | 1.2 m |
| 7.74 | 16° | RIGHT | North Lincoln Memorial Drive | 0.9 m |
Zone total: 33 m ≈ 9 sec.
D · Lake Parkway & the turnaround the single biggest bend on the course
| Mile | Bend | Run | Where | Saves |
|---|---|---|---|---|
| 9.81–10.16 | 49° | RIGHT | John R. Plewa Memorial Lake Parkway | 2.6 m |
| 10.23–10.40 | 231° | LEFT | John R. Plewa Memorial Lake Parkway | 7.0 m |
| 10.42–10.57 | 51° | RIGHT | John R. Plewa Memorial Lake Parkway | 2.7 m |
| 10.64–10.99 | 49° | LEFT | John R. Plewa Memorial Lake Parkway | 2.6 m |
Zone total: 15 m ≈ 4 sec.
E · Off the bridge to the line Clybourn, final left
| Mile | Bend | Run | Where | Saves |
|---|---|---|---|---|
| 12.66–12.93 | 23° | RIGHT | Lake Freeway | 1.2 m |
| 13.06 | 81° | RIGHT | East Clybourn Street | 4.3 m |
Zone total: 6 m ≈ 2 sec.
Execution Rules
- Commit to a side and stay there through a sequence, don't weave. Miles 2.1–3.5 are five turns in 1.4 mi. Crossing the road between every one costs more lateral metres than the corners save. Ride the bend-to-bend colour on the map: it already accounts for this.
- Aid stations outrank tangents. Six stations, and a station on the wrong side of a bend costs about 2 m of tangent while a missed cup costs the rest of the race. Take the cup, then drift back to the line. Do not plan a fluid approach around a corner.
- The turnaround at 10.37 is the one bend to actually rehearse. 231° of total direction change in 278 m, and it sits immediately after the mile-10 gel-and-water station and immediately before the 1.94-mile climb that decides the race. Round it tight on the inside, then re-settle to 7:38 within 20 sec — the natural error here is a hot quarter off the turn, which is exactly the restart burst that has shown up three times in this build.
- The pack outranks all of it. If you're in the 1:40 group, run the group's line, not yours. Wind shelter on an exposed lakefront is worth more than 115 m, and fighting for a tangent inside a pack is how you get tripped.
- Don't chase the line on the two bridge climbs. Mile 8 and miles 11–12 are effort-governed. Adding a navigation task to a climb you're already rationing is a bad trade for the 1–2 m available there.
The Twelve That Pay
| Mile | Bend | Run | Where | Saves |
|---|---|---|---|---|
| 10.23–10.40 | 231° | LEFT | John R. Plewa Memorial Lake Parkway | 7.0 m |
| 3.38–3.50 | 114° | LEFT | North Lake Drive | 6.0 m |
| 4.30 | 105° | RIGHT | North Lincoln Memorial Drive | 5.5 m |
| 3.71 | 180° | RIGHT | East Newberry Boulevard | 5.0 m |
| 3.14–3.36 | 92° | LEFT | North Terrace Avenue | 4.8 m |
| 2.12 | 90° | RIGHT | East Lafayette Place | 4.7 m |
| 2.17–2.36 | 89° | LEFT | East Lafayette Place | 4.6 m |
| 2.76–2.86 | 88° | LEFT | North Wahl Avenue | 4.6 m |
| 3.93–4.04 | 86° | LEFT | North Lake Drive | 4.5 m |
| 2.75 | 83° | RIGHT | North Terrace Avenue | 4.4 m |
| 0.73–0.78 | 82° | LEFT | East Wisconsin Avenue | 4.3 m |
| 13.06 | 81° | RIGHT | East Clybourn Street | 4.3 m |
Source: half_marathon.gpx (333 pts, 13.125 mi) · bends clustered from
per-vertex heading change, threshold 15°, 260 m gap · road names reverse-geocoded from OSM
· savings modelled at a 3 m inside offset from the OSM road centreline. The GPX is a road
centreline, not the coned race course, so treat mile positions as ±0.02 and treat the geometry
as the shape of each bend rather than its exact width.