Free Transportation and Pavement Software — SUMO, MATSim and the Rest
Transport planning is a field where the commercial packages (VISSIM, Aimsun, TransCAD) run to tens of thousands a year — and where, at the same time, the free tools are not a compromise but recognised research tools that papers are published with. Here is what exists, sorted by the size of the problem you are solving.
Microscopic traffic simulation — a junction and a street
1. SUMO
Simulation of Urban MObility, from the German aerospace agency DLR. It simulates every vehicle individually: driver decisions, lane changing, signals, public transport, pedestrians and cyclists. The network is imported directly from OpenStreetMap, and a Python API (TraCI) lets you control the simulation while it runs — to test an adaptive signal algorithm, for instance.
What is missing: there is no network editor at VISSIM's level, and calibrating a model takes manual work. The visualisation is functional rather than impressive — if the deliverable is a video for a client, that is worth weighing.
2. MATSim
An entirely different level: an agent-based model of a whole city or metropolitan population. Every person gets a daily activity plan — home, work, shopping — and the model iterates until travel behaviour stabilises. This is the tool for policy-level questions: what a new light rail line, congestion pricing, or a shift in working hours would do.
What is missing: it needs population data and a travel survey. Without good data it is a beautiful model saying nothing.
SUMO
German Aerospace Center (DLR) / Eclipse
Microscopic traffic simulation — every vehicle modelled individually on a real road network.
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MATSim
ETH Zurich / TU Berlin
Agent-based transport simulation at city scale — activities, routes and mode choice.
Get it from the vendorPavement design
3. PAVEXpress
Flexible and rigid pavement thickness design from traffic, subgrade and material inputs, following AASHTO, with a saveable summary. Registration is free.
4. Pavement Designer
From the American Concrete Pavement Association — thickness design for concrete pavements and overlays, including industrial and airport sections.
A warning that applies to both: the design methods, traffic data and climate factors are American. They are excellent for understanding methodology and for an order-of-magnitude check — they are not a substitute for your local standard and local road data.
PAVEXpress
National Asphalt Pavement Association
Online pavement thickness design based on AASHTO methods.
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Pavement Designer
American Concrete Pavement Association
Concrete pavement design from the American Concrete Pavement Association.
Get it from the vendorWhat you need around it — and this is where most time is saved
Most of the work on a transport project is not the simulation but preparing the data and presenting the result:
- QGIS — building the network, importing OpenStreetMap, spatial queries and map production. It accompanies every stage.
- GRASS GIS — elevation models, grades along an alignment and sight-distance analysis at junctions.
- HEC-RAS — cross-road drainage and culverts. On a road project this is almost always part of the work.
- Python — processing simulation output, statistical analysis and plotting. Both SUMO and MATSim are driven from it.
- WebODM — drone imagery into an orthophoto and elevation model of a site or road section.
QGIS
QGIS.org
Open-source GIS for spatial analysis, layer work and map production.
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GRASS GIS
OSGeo
GIS with strong raster and terrain analysis — catchments, slope, visibility and elevation models.
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HEC-RAS
US Army Corps of Engineers
1D/2D hydraulic model for rivers, bridges and culverts, with floodplain mapping. The world standard.
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Python
Python Software Foundation
The language behind most modern engineering computation, and its full ecosystem.
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WebODM (OpenDroneMap)
OpenDroneMap
Photogrammetry from drone imagery — orthophoto, elevation model, point cloud and textured 3D model.
Get it from the vendorWhere to start
For a junction- or street-level question — SUMO, with a network imported from OpenStreetMap. You can have a running simulation within a day.
For a city- or policy-level question — MATSim, but only if you have population data. Otherwise you will build an impressive model that says nothing.
And for pavement design — start with the American tools to understand the method, then do the calculation under the standard you actually have to submit against.
More in this area: transport engineering · civil engineering · GIS tools.