Computer program predicts vehicle pollution
Svein Tønseth
Planners in large Norwegian cities are using a computer simulation model to see how changes in the traffic system affect traffic flow. At NTH, graduate student Torbjørn Haugen is developing a computer model to predict the consequences of such measures on local air quality as well.
Linking up traffic and the environment. Graduate student Torbjørn Haugen is developing a new computer tool that analyses vehicle emissions for traffic planning.
For example, what is the effect of changing traffic signal timing at the edge of the city on air quality in the city centre? Or what happens to the air quality in district A if a new road is built from district B to district C? The Directorate of Public Roads has awarded Haugen a fellowship to develop a computer program that will enable planners to answer questions such as these.
Modeling peak hour traffic
For this project, Haugen is using a detailed computer-based simulation model which is already in use for traffic planning in most major Norwegian cities. The British traffic model, which is known as "CONTRAM", predicts how a given change in a road network or in a control system at a road junction affects traffic flow throughout the network. The high degree of detail in the model means that it is particularly suitable for simulations of peak hour traffic.When it is fed with detailed information about the road network and data on where car-owners live and work, the CONTRAM model can be used to calculate how a new roundabout or the closure of a city centre street affects the traffic in the town's road network. The model generates data on speeds and the length of queues, information about how many stops drivers can expect between junction A and junction B, and how long they will have to stand with their engines idling.
Environmental aspect
Torbjørn Haugen is currently adding an environmental aspect to this model. His program shows how the estimated changes in traffic distribution and conditions will effect vehicle emissions in different parts of a city. The model deals with carbon monoxide (CO) and nitrogen dioxide (NO2), two of the three primary emissions that are measured in environmental tests of vehicles."The choice of emissions to model was clear, because at present, the relationship between traffic condition and emissions is best known for these two gases," explains Haugen. The new program will be a central part of his doctoral thesis at NTH's Department of Transport Engineering. He expects the program to be ready by the end of 1994.