Simulation/Motorways
Contents
Motorway Simulation
This page describes simulations of motorways in SUMO. It aims to collect best practices when modelling motorway networks and traffic.
Building a network for motorway simulation
Networks can be imported from any supported data source or created from scratch with NETEDIT. Depending on the level of detail special processing may be necessary
Motorway ramps
If the network does not contain detailed ramp data, NETCONVERT can be configured to add them heuristically. This basically adds acceleration at on-ramps and deceleration lanes at off-ramps.
Combined On-Off-Ramps
Combined ramps are those where the acceleration lane from an on-ramp becomes the deceleration lane for a nearby off-ramp. This forces vehicles into a weaving pattern where entering and exiting vehicles need to swap lanes. This type of situation may cause deadlocks in SUMO unless preventive measures are taking. The problem is exacerbated if the acceleration/deceleration lane is short or traffic is very dense.
To prevent deadlocks the connection pattern shown in the following image should be used. Note, that the off-ramp is targeted by the two rightmost lanes of the preceding edge and lane 0 has priority over lane 1. Vehicles exiting the motorway will attempt to move to the rightmost lane if possible but can still continue their route if that lane is occupied.
In version 0.25.0 and earlier, this connectivity is not supported and the option --time-to-teleport.highways may be used to resolve deadlocks via teleporting.
