Demand/Introduction to demand modelling in SUMO

After having generated a network, one could take a look at it using SUMO-GUI, but no cars would be driving around. One still needs some kind of description about the vehicles. This is called the traffic demand. From now on we will use the following nomenclature: A trip is a vehicle movement from one place to another defined by the starting edge (street), the destination edge, and the departure time. A route is an expanded trip, that means, that a route definition contains not only the first and the last edge, but all edges the vehicle will pass. SUMO and SUMO-GUI need routes as input for vehicle movements. There are several ways to generate routes for SUMO. The choice depends on your available input data:

  • Using flow definitions

    This is mostly the same approach as using trip definitions, but one may join vehicles having the same departure and arrival edge using this method

  • Using Randomization

    This is a quick way to get some traffic if you do not have access to any measurements but the results are highly unrealistic. See Tools/Trip#randomTrips.py

  • Using flow definitions and turning ratios

    One may also leave out the destination edges for flows and use turning ratios at junctions instead. See JTRROUTER.

  • Using detector data (observation points)

    Induction loops and similar devices are commonly used by authorities to measure traffic. Using DFROUTER you may uses this data to generate demand. See Demand/Routes_from_Observation_Points.

By now, the SUMO-package contains four applications for generating routes. DUAROUTER is responsible for importing routes or their definitions from other simulation packages and for computing routes using the shortest-path algorithm by Dijkstra. Additionally, in combination with the simulation, the DUAROUTER can compute the dynamic user assignment formulated by C. Gawron. JTRROUTER may be used if you want to model traffic statistically, using flows and turning percentages at junctions. OD2TRIPS helps you to convert OD-matrices (origin/destination-matrices) into trips. The DFROUTER computes routes from given observation point measures.