A Review of Guidelines for Applying Traffic Simulation to Level-of-service Analysis

Microscopic traffic simulation is often used as an alternative or complementary tool to analytical methods and procedures for level-of-service analyses of road traffic facilities. The increased usage of traffic simulation for level-of-service analysis has raised a need for guidelines on how to apply and use traffic simulation models. Many countries have developed or are currently developing traffic simulation guidelines. This is also the case in Sweden, were the new Swedish highway capacity manual will include a chapter on traffic simulation. This paper presents a survey of the current traffic simulation guidelines in USA, Germany, UK, Denmark and Sweden. The guidelines have been analysed with respect to the aspects covered: when to apply simulation; the workflow of a simulation study; data collection needs; calibration and validation; experimental design; statistical analysis; and calculation of level-of-service measures. The guidelines analysed are focused on different aspects and none of them covers all of the topics listed above. Some of the guidelines are connected to specific simulation software packages and some are written in a more general manner. Most of the aspects covered are general and applicable in any country. The main reason for developing country specific guidelines is often a need for guidelines in the local language. Experimental design and statistical analysis are not treated extensively in the guidelines; neither do the guidelines discuss how to deal with calibration based on limited real world measurements. Calculation of level-of-service measures are quite extensively treated in some of the guidelines and to a little extent in others. All of the guidelines contain important contributions for the simulation chapter of the new Swedish highway capacity manual. © 2011 Published by Elsevier Ltd.