Highway Roads
v0.5.0Build 4-, 8-, and 16-tile asphalt highways for T1/T2, T3, and massive T4 traffic, with ramps and automatic routing.
- Source code
- https://github.com/max2605/CoI_Roads
Highway Roads
ALPHA
Highway Roads is still under active development. Please report any issues you encounter.
Build a complete high-speed road network for your island. Highway Roads adds smoothly planned, two-way roads for Captain of Industry vehicles—including terrain-following ramps, flowing curves, intersections, and roundabouts.
Build Roads Without Limits
The multi-pivot construction tool supports:
- Long, flowing curves
- Repeated S-bends
- Seamless, tangent-continuous extensions
- Native 12.5% and 25% terrain slopes
- Automatically smoothed ramps
- Precise snapping to existing roads, intersections, and roundabouts
- All 16 planning directions in 22.5° increments
Roads check their entire width for sufficient terrain support. Unsupported floating sections and invalid water crossings are rejected automatically.
Intersections and Roundabouts
Create complete road networks using:
- Three-way T-junctions
- Four-way cross intersections
- Roundabouts designed for right-hand traffic
- Automatic selection of a suitable available connection
- Direct snapping by clicking a visible intersection or roundabout
Roundabout approaches include the additional space required for merging and exiting, allowing valid connections to be placed reliably.
Automatic Vehicle Routing
Vehicles automatically compare their normal route with reachable highway alternatives. They enter and leave the highway at suitable connections and remain aligned with their lane through curves, intersections, and terrain ramps.
On suitable Highway Roads segments, road-capable vehicles can:
- Reach up to 140% of their normal maximum speed
- Use only 50% of their normal maintenance
- Automatically transition between terrain and mod roads
- Fall back to the regular game route when no suitable highway route exists
When both routes have similar travel costs, the traffic director prefers the highway.
Performance
Version 0.3.4 significantly improves performance during active terrain work:
- Vehicles already using a highway retain their current native road route
- Expensive additional searches are limited to the four best candidates
- Per-vehicle, per-tick log messages have been removed
- Route handling remains considerably more stable during excavation and dumping
Performance still depends on your hardware, map, vehicle count, and road network. Testing has included saves with up to 500 trucks.
Controls
- Left-click: Place the starting point and additional pivots
- Double-click: Build the planned road
- Shift + double-click: Build and continue directly from the completed endpoint
- Right-click: Cancel construction
Separate on-ramp and off-ramp tools are not required.
Compatibility
Highway Roads 0.3.4 is designed for Captain of Industry 0.8.6 through 0.8.6c and can be added to existing saves.
Important: After Highway Roads pieces have been built and the game has been saved, the mod should not be removed from that save.
Why Does CoI Hub Report “Uses Reflection by Name”?
Highway Roads uses reflection in a small, fixed set of places because the Captain of Industry mod API does not publicly expose everything required for its highway behavior.
Reflection is used to:
- Instantiate the game’s native vehicle pathfinder
- Temporarily adjust vehicle speed and steering state
- Keep vehicles aligned with curved highway lanes
- Apply the highway speed bonus
- Set the toolbar icon
All referenced type and member names are fixed and visible in the public source code. The reflection code does not load external assemblies, access the network or filesystem, launch processes, or collect user data.
The practical risk is compatibility: if a game update renames these internal members, the mod may stop working until an updated version is released. This is why Highway Roads specifies the game versions it has been tested with.
Highway Roads 0.5.0 – Wide T3/T4 Roads & Multilane Traffic
Highway Roads 0.5.0 is now available!
This update introduces properly sized roads for heavy T3 trucks and massive modded T4 vehicles:
- New 8-tile T3 roads with one full-width lane per direction.
- New 16-tile T4 highways with two full-width lanes per direction.
- Faster vehicles prefer the inner passing lane, while slower traffic uses the outer driving lane.
- Full support for curves, S-bends, G4/G8 ramps, elevation controls and concrete supports.
- Construction costs now scale with the actual road width.
- Separate construction tools for T1/T2, T3 and T4 roads.
- Complete MultiLangLib localization with 22 language catalogs.
- Existing T1/T2 roads and saved entities remain compatible.
Please note: lane selection currently happens before the journey. Dynamic lane changes and live overtaking are not enabled yet. Intersections and roundabouts remain limited to T1/T2 roads in this release.
Requires Captain of Industry 0.8.6c and MultiLangLib 0.1.0 or newer.
The mod can be added to existing saves. Do not remove it after Highway Roads entities have been built.
New Version - Ramps and Asphalt
Hello, only a short messages.
I got Ramps in it with Q and E can you up or lower it. And Streets costs now Asphalt and Gravel to build.
Highway Roads 0.3.4
🚧 Highway Roads 0.3.4 – Major Update Since Version 0.1.0!
Highway Roads has come a long way since its initial release. What began as a simple highway construction tool has now evolved into a complete road system for Captain of Industry.
🏔️ Terrain Ramps (Somewhat/WIP)
Highways can now follow the terrain uphill and downhill.
- Native 12.5% and 25% slopes
- Automatically creates gentle ramps when enough space is available
- Level transitions at the beginning and end of ramps
- No floating roads or unauthorized water crossings
- Checks the entire road width for sufficient terrain support
🔀 Intersections and Roundabouts
New additions include:
- Three-way T-junctions
- Four-way cross intersections
- Roundabouts for right-hand traffic
- All 16 planning directions in 22.5° increments
- Automatic selection of the appropriate available connection
- Direct snapping by clicking the visible intersection or roundabout
Roundabout entrances also account for their longer merging and exit sections, preventing valid connections from being incorrectly rejected as collisions.
🛣️ Improved Road Construction
The tool continues to support:
- Long, smooth curves
- Multiple pivot points
- Repeated S-curves
- Seamless extensions without sharp bends
- Precise snapping to existing highway connections
- Continuing construction with Shift + double-click
Separate on- and off-ramps are still not required.
🚛 Automatic Vehicle Routing
Vehicles automatically compare their regular route with available highway routes.
- Up to 140% of their normal maximum speed
- Only 50% of the normal maintenance requirement while driving on mod roads
- Lane-following behavior through curves and while traveling uphill or downhill
- Automatic transitions between terrain and highways
- Falls back to the regular game route if no suitable highway route exists
⚡ Performance Improvements
Terrain work could previously trigger numerous route recalculations and thousands of log entries. Version 0.3.4 resolves this performance issue:
- Vehicles traveling on highways retain their current native road route
- No more log entries for every vehicle during every simulation step
- Additional searches are limited to the four best candidates
- Significantly more stable performance during active terrain work
💾 Compatibility
Highway Roads 0.3.4 is designed for Captain of Industry versions 0.8.6 through 0.8.6c and can be added to existing save files.
Important: Once mod roads have been built and the game has been saved, the mod should not be removed from that save file.
Thank you for testing and for your feedback—have fun building your highway network! 🚛🛣️
v0.5.0
Latest- Game version
- 0.8.6c - 0.8.6c
- Released
- Aug 11, 2026
- File size
- 121.7 KB
- License
- MIT
Wide T3/T4 roads and deterministic multilane routing * Added an eight-tile T3 road with one native four-tile lane per direction for heavy vehicles. * Added a sixteen-tile T4 road with two native four-tile lanes per direction through straights, curves, S-bends, and G4/G8 elevation pieces. * Added separate localized T1/T2, T3, and T4 construction tools with profile-width previews, validation, supports, snapping, and width-scaled costs. * Added complete MultiLangLib catalogs for all 21 official game locales plus a neutral Portuguese fallback, with 56 player-facing texts in each catalog. * Added deterministic T4 lane selection: faster vehicles prefer the inner passing lanes while slower vehicles prefer the outer driving lanes. * Bundled every wide-road end into one physical snap target while exposing all lane endpoints to vehicle routing. * Preserved all existing T1/T2 prototype IDs, geometry, and lane ordering; the new T3 and T4 families use separate save-stable V1 IDs. * Kept dynamic mid-route lane changes disabled because Captain of Industry 0.8.6c provides no safe rear-gap and lane-change reservation API; version 0.5.0 selects a lane before the trip. * Verified Captain of Industry 0.8.6c. The mod can be added to saves but must not be removed after highway entities have been built.
v0.4.1
- Game version
- 0.8.6 - 0.8.6c
- Released
- Aug 07, 2026
- File size
- 71 KB
- License
- MIT
Elevated supports and localized controls * Added the configurable RaiseUp and LowerDown controls used by the train construction tool, including its E/Q defaults and toolbox buttons. * Added concrete supports at native train-track pillar candidate positions for inclined and raised flat road pieces. * Extended cursor elevation from ground level to the native six-tile train-pillar limit in one-tile steps. * Allowed connected plans with visibly supported flat G0 pieces to complete immediately as one atomic batch while near-ground plans retain normal material costs. * Prevented terrain from burying the thin highway deck at the upper end of a ramp.
v0.3.4
- Game version
- 0.8.6 - 0.8.6c
- Released
- Aug 06, 2026
- File size
- 61.8 KB
- License
- MIT
Stable junction snapping and terrain reroutes * Stabilized direct snapping to visible junction and roundabout bodies, with nearby arms taking priority. * Expanded roundabout collision checks to cover the longer merge and exit area. * Kept vehicles on their current native road route when terrain work triggers route updates. * Removed per-vehicle simulation-step routing logs and limited additional route searches to the best candidates.
v0.1.0
- Game version
- 0.8.6 - 0.8.6c
- Released
- Aug 04, 2026
- File size
- 43.4 KB
- License
- MIT
Initial public release * Added smoothly planned two-way highways with flowing curves, repeated S-bends, and tangent-continuous extensions. * Added multi-pivot construction and exact endpoint continuation with Shift-double-click. * Added automatic comparison between normal routes and reachable highway alternatives, including automatic entry and exit. * Added lane-following movement through curves, up to 140 percent road speed, and 50 percent base maintenance usage. * Added fallback to the normal game route when no suitable highway route exists.
v0.5.0 | 2026-08-11
Wide T3/T4 roads and deterministic multilane routing * Added an eight-tile T3 road with one native four-tile lane per direction for heavy vehicles. * Added a sixteen-tile T4 road with two native four-tile lanes per direction through straights, curves, S-bends, and G4/G8 elevation pieces. * Added separate localized T1/T2, T3, and T4 construction tools with profile-width previews, validation, supports, snapping, and width-scaled costs. * Added complete MultiLangLib catalogs for all 21 official game locales plus a neutral Portuguese fallback, with 56 player-facing texts in each catalog. * Added deterministic T4 lane selection: faster vehicles prefer the inner passing lanes while slower vehicles prefer the outer driving lanes. * Bundled every wide-road end into one physical snap target while exposing all lane endpoints to vehicle routing. * Preserved all existing T1/T2 prototype IDs, geometry, and lane ordering; the new T3 and T4 families use separate save-stable V1 IDs. * Kept dynamic mid-route lane changes disabled because Captain of Industry 0.8.6c provides no safe rear-gap and lane-change reservation API; version 0.5.0 selects a lane before the trip. * Verified Captain of Industry 0.8.6c. The mod can be added to saves but must not be removed after highway entities have been built.
v0.4.1 | 2026-08-07
Elevated supports and localized controls * Added the configurable RaiseUp and LowerDown controls used by the train construction tool, including its E/Q defaults and toolbox buttons. * Added concrete supports at native train-track pillar candidate positions for inclined and raised flat road pieces. * Extended cursor elevation from ground level to the native six-tile train-pillar limit in one-tile steps. * Allowed connected plans with visibly supported flat G0 pieces to complete immediately as one atomic batch while near-ground plans retain normal material costs. * Prevented terrain from burying the thin highway deck at the upper end of a ramp.
v0.4.0 | 2026-08-06
Resource-supplied asphalt construction * Added asphalt as a storable loose product and a 19 gravel plus 1 heavy oil recipe for Industrial Mixers I and II. * Replaced free placement with native construction sites and truck delivery for horizontal highway pieces and nodes. * Added length-based road costs and area-based junction and roundabout costs. * Set each rounded-up horizontal road tile to 2 gravel for the foundation and 1 asphalt for the surface. * Allowed genuine G4/G8 ramp pieces to span lower dry terrain while keeping flat G0 surfaces terrain-bound. * Prevented unfinished inclined pieces from deadlocking their own material deliveries by completing those sub-pieces immediately. * Improved ramp planning, endpoint snapping, exit-candidate limits, and completed-network routing checks.
v0.3.4 | 2026-08-06
Stable junction snapping and terrain reroutes * Stabilized direct snapping to visible junction and roundabout bodies, with nearby arms taking priority. * Expanded roundabout collision checks to cover the longer merge and exit area. * Kept vehicles on their current native road route when terrain work triggers route updates. * Removed per-vehicle simulation-step routing logs and limited additional route searches to the best candidates.
v0.3.1 | 2026-08-06
Terrain-following elevation ramps * Added terrain-following highway ramps with native 12.5 percent and 25 percent grades. * Added horizontal transitions at ramp starts, ramp ends, pivots, and network connections. * Added full-width validation for terrain support, water, map edges, and occupied terrain. * Added three-dimensional lane following through curves and elevation changes. * Added automatic flat-approach retries at free road endpoints.
v0.2.0 | 2026-08-05
Junctions and roundabouts * Added three-arm T-junctions, four-arm cross intersections, and four-arm roundabouts for right-hand traffic. * Added all 16 placement directions in 22.5-degree increments. * Added exact snapping to free network ports and automatic selection of a suitable free arm. * Added geometry smoke tests for roads, intersections, roundabouts, snapping, routing, and collision validation. * Replaced the standalone ramp tool with the unified highway-network construction system.
v0.1.0 | 2026-08-05
Initial public release * Added smoothly planned two-way highways with flowing curves, repeated S-bends, and tangent-continuous extensions. * Added multi-pivot construction and exact endpoint continuation with Shift-double-click. * Added automatic comparison between normal routes and reachable highway alternatives, including automatic entry and exit. * Added lane-following movement through curves, up to 140 percent road speed, and 50 percent base maintenance usage. * Added fallback to the normal game route when no suitable highway route exists.
- MultiLangLib ≥ 0.1.0
No other mods depend on this mod yet.