Roadcraft: Priority roundabouts

Experimental release 1.3.

Allows to automatically assign actual traffic priority to roundabouts and to add European style visual roundabout and lane management signage.

Changenotes — Version 1.3

This version identifies the release; the Mod Hub may display a different version number.

• Added support for four-lane roundabouts. Both middle lanes continue circulating alongside the existing inner lane; the outer lane remains for exits.
• Fixed reapplication after road changes when the game returns unchanged pedestrian crossings in a different order.
• Updated sign metal textures and added twelve stable finish variations, improved shadows from both lighting directions and extended posts slightly farther into the ground while preserving sign height.

How to use

Open Roads → Tools → Roadcraft: Priority roundabouts. Hover a closed one-way loop or a directly connected approach. Click to apply, click again to remove, or reapply after changing its appearance or road layout. Escape closes the tool. Keep the tool open until an update finishes.

Priority strength affects single-lane roundabouts only. Stronger settings give circulating traffic longer priority periods and entering traffic longer waits. Given how the game routes traffic internally this can contribute to gridlock, rather than solve it. So revert to gentler settings if the priority is enforced too extremely. Two-, three- and four-lane roundabouts are managed automatically: outer lanes exit, inner lanes circulate (including both middle lanes on four-lane rings) and entrants join the outer lane. At entry-only junctions, outer circulation is redirected inward. Multi-lane traffic shares a fixed vehicle priority while still allowing pedestrians through at crosswalks.

Appearance offers: Entrance signs as default (roundabout signs appear at each approach to the roundabout), Entrance + lane signs (lanes within the roundabout show where a car can turn or continue), or showing in-game traffic lights. All three appearances use the same existing in-game control logic. Removing priority restores previous road and junction settings.

Rings must have a consistent lane count. Tram tracks, bus lanes and several entry or exit roads at one multi-lane junction are not supported yet, neither are junctions where multiple roads exit the roundabout from the same exit node.

Controller controls

Follow the game’s native controller prompts to open settings, change values and return to the utility.

Controller placement and toolbar settings have been tested with an Xbox controller on PC. Console hardware and other controller families have not been verified.

How it works under the hood

The mod combines the game's existing lane connections and traffic-light phases to simulate roundabout priority. It does not introduce a new traffic priority system. Single-lane roundabouts use alternating signal phases; multi-lane roundabouts also use lane restrictions to allow compatible movements together. Choosing signs conceals the traffic lights while retaining their control logic. TPF2 did not expose an addressable priority system, and I have not found an equivalent in the TPF3 modding API. I therefore use the available junction controls as a workaround.

Savegame compatibility

The mod can be added to an existing save. In removal testing, the save could still be loaded, but the signs became placeholder models. These can be cleared by resetting the affected junction settings (ie placing traffic lights or choosing the automatic settings). Before disabling the mod, preferably remove its applied priority using the tool to restore the original road and junction settings.

Feedback requested

I would appreciate feedback in the comments about unexpected behaviour, crashes, and whether the mod can be operated on consoles using a controller.

Earlier changenotes

Version 1.2

This version identifies the release; the Mod Hub may display a different version number.

• Improved roundabout and lane-sign visuals: weathered metal, smoother plate edges, longer posts and mounting fasteners.
• Improved sign-face reflections under angled lighting and at night.
• Fixed an application failure affecting some newly built roundabouts.

Version 1.1

This version identifies the release; the Mod Hub may display a different version number.

• Added experimental controller support.