Motivation
- intersection is the bottleneck of urban traffic
- intersection is very different from the highway, which means that the highway model may not be applicable
Model
role of traffic light
- assign access to different lanes
We can just consider one direction first. The other direction can be attained by symmetry.
Key factors of congestion in intersections
- When the traffic light turns from red to green, all waiting cars starts from speed 0.
- The destination of each car is different. The left-turn takes more time, since it may collide with the cars from the opposite direction.
One Intersection
- Car follower model may be applied to model the traffic when the traffic light turns green.
- rate_all = rate_right + rate_straight + rate_left
- What is the critical input arrival rate?
- Traffic lights separate the left-turn traffic from others. Better efficiency?
From One Intersection to Urban Road Topology
- Urban road topology can be constructed by connecting several intersections.
- The simplest case is grid road topolgoy (Manhattan model), where the distance between intersections should be specified.
- Will there be any cascade effect of delay in the network?
Reference
- An extended car-following model at signalized intersections, Physica A: Statistical Mechanics and its Applications, 2014.
- Review of road traffic control strategies, Proceedings of the IEEE, 2003.