Abstract

In the course of the Telematics implications Programme Transport of the European Commission Fourth Framework Research Programme much attention is devoted to evaluation and demonstration. This report is part of the DACCORD project TR1017, devoted to the development and application of co-ordinated traffic control in freeway corridors. The report presents an evaluation plan for the Fourth Framework programme DACCORD. An extensive methodology has been applied to prepare a systematic and comprehensive evaluation plan. It contains an analysis assessment objectives, specification of performance indicators enabling evaluation at distinct levels of assessment (i.e. technical level, user-acceptance, impact analysis, and socio-economic assessment) and a description of various tools for validation. The plan has been developed to be site-independent to a large extent, thereby maximising the potential for cross-comparison, by proposal of common verification and demonstration plans for distinct sites. Additionally, the evaluation plan enables harmonisation of results from other European ATT-projects.

Abstract

In traffic flow analysis several regimes are distinguished, such as congested and non-congested flow conditions. Indications exist that driving behavior differs by regime, and that it may change discontinuously between regimes. In contrast, most traffic flow models used today basically assume the same car-following behavior irrespective of the traffic flow regime. It is hypothesized that because of this deficiency, these models do not always perform satisfactorily. To clarify this issue, differences in car-following between congested and non-congested flow are analyzed with data from two sites on Dutch freeways. It is shown that, at the same speeds, passenger car drivers follow with smaller headways in non-congested flow than in congested flow. Car-following of truck drivers does not show differences between regimes. Microscopic distance gap - speed models are established for several road user classes, valid for each of the two flow regimes. To show the improvements resulting from these new microscopic relationships, the latter are implemented in a micro simulation model (FOSIM) with which macroscopic patterns in traffic flow are modeled. The macroscopic findings produced with the regime specific car-following rules show a considerable improvement in modeling performance.

Abstract

In the course of the Telematics implications Programme Transport of the European Commission Fourth Framework Research Programme much attention is devoted to evaluation and demonstration. This report is part of the DACCORD project TR1017, devoted to the development and application of co-ordinated traffic control in freeway corridors. The report presents an evaluation plan for the Fourth Framework programme DACCORD. An extensive methodology has been applied to prepare a systematic and comprehensive evaluation plan. It contains an analysis assessment objectives, specification of performance indicators enabling evaluation at distinct levels of assessment (i.e. technical level, user-acceptance, impact analysis, and socio-economic assessment) and a description of various tools for validation. The plan has been developed to be site-independent to a large extent, thereby maximising the potential for cross-comparison, by proposal of common verification and demonstration plans for distinct sites. Additionally, the evaluation plan enables harmonisation of results from other European ATT-projects.