Road building
Traffic Architect Bridge & Tunnel Levels
In Traffic Architect Demo 1.0.7, Bridge and Tunnel have selectable levels: press B or T again to change the respective level. A ground-level bridge crosses a river at the road’s height without ramps; a ground-level tunnel goes through rock. A continuous drag can become road on land, bridge over water and tunnel through a mountain.
On this page
Choose a terrain crossing or a different road level
| What you want | Choose and inspect |
|---|---|
| Cross water without a raised approach | Ground-level bridge; check that the preview stays at road height. |
| Go straight through a mountain | Ground-level tunnel; inspect the preview through the rock and at both ends. |
| Use a different height/depth | Cycle the relevant Bridge/Tunnel level and inspect the resulting route before building. |
“Bridge” does not automatically mean “raised bridge with ramps.” The 1.0.7 change specifically adds the flat terrain-crossing option. The patch does not list a numeric level order, so this guide does not tell you to press B or T a fixed number of times from an assumed starting mode.
Build the intended crossing
- Pause while planning so an unwanted eligible build can be undone before resuming.
- Select Bridge or Tunnel for the crossing you need. Press B or T again to cycle that tool’s level.
- Look at the active preview, rather than relying on a remembered number of key presses. Choose the ground-level mode for a flat river or mountain crossing.
- Drag the intended route across the terrain. In the documented ground-level behavior, land uses road, water uses bridge and rock uses tunnel within that drag.
- Inspect both ends, the road direction and any nearby roads. Commit only a preview that follows your intended route.
- Check the finished endpoints before running traffic. For an eligible mistaken build, use Ctrl+Z while still paused.
One-way tunnels display their direction in 1.0.7. Inspect it when a visually connected crossing still does not provide the travel direction you need.
If the preview or connection looks wrong
- You expected a flat river crossing but see a raised route: recheck the selected Bridge level and preview; the tool name alone is insufficient.
- The route crosses another road above or below it: do not infer a junction merely from overlapping lines. Inspect the endpoints and intended connection.
- The build is refused: read the current refusal and preserve the preview for a report. The sources do not establish one clearance, slope or ramp recipe for every obstacle.
- A short piece next to a bridge will not upgrade: full 1.1.0 specifically announces a fix for that case. Check your Demo/full distinction and version, then use the road-editing checks.
The 1.0.7 notes also fix a drag across another bridge/tunnel producing tiny pieces or cutting unrelated crossed roads. That is a published fix, not a promise every geometric crossing now connects.
The crossing is ready when the finished route uses the intended level, terrain transitions and travel direction, and its endpoints join the roads you actually need. A route passing over another road is not by itself evidence of a usable junction.
Sources & version
Controls and mixed-terrain behavior: official Demo 1.0.7 announcement, complete body reread November 3. Bridge-adjacent upgrade fix: official full 1.1.0 announcement, published November 3 at 18:01:35 UTC and read in full.
The installed Demo build and its parity with full 1.1.0 were not observed. This is a documented-control and preview-check guide, not a session-tested construction or an exact engineering-clearance table.