This study explores the traffic flow impacts of the application of narrow lanes. Narrow lanes can be applied with the aim of optimal utilisation of existing roads in congested networks. The basic idea of narrow lanes is that the existing road cross section, consisting of traffic lanes and an emergency lane, is redesigned into a cross section with an extra traffic lane while maintaining the emergency lane. The MICroscopic model for Simulation of Intelligent Cruise control (MIXIC) has been extended with additional models that represent driver behaviour on narrow lanes. The extended MIXIC model has been applied in an exploratory study of 3 design variants: a reference design with two traffic lanes of normal width, a minimum design with three narrow traffic lanes of strongly reduced width, and a maximum design with three narrow traffic lanes of slightly reduced width. For each design, several variants have been evaluated: using a speed limit of 70 or 90 km/h, and a traffic demand with 20%, 10% or 0% of freight traffic (both large and small trucks). These designs were used in simulations where traffic was led into a bottleneck consisting of narrow lanes. Traffic safety and traffic performance criteria were formulated, and the impact of speed limit, percentage of freight traffic and lane width with respect to these criteria were formulated.
Abstract