Estelle Chevallier

Modeling unsignalized intersections at macroscopic and micrsocopic scales: issues and proposals

Driving experience and on-field data reveal two distinct traffic patterns at unsignalized intersections: (i) when the conflict area is uncongested, minor stream vehicles search for acceptable time intervals between major stream vehicles to complete the insertion manoeuvre; (ii) when the conflict area is congested, minor stream vehicles do not respect the give-way rule anymore and adopt an alternating behaviour with queued vehicles of the major road to enter the merge.

These observed traffic patterns are well described by the gap acceptance theory in uncongested regime and by the demand-supply framework in congestion. However, current dynamic microscopic and macroscopic insertion models are exclusively based on either one or the other theoretical background. The resulting modelling errors in terms of flows estimation will be highlighted in this presentation. This can be devastating in practice as capacity and delays can be misestimated. For each kind of traffic flow representation, some insights will be also proposed to avoid these errors by modelling both operation regimes within the same framework.