Variable Speed Limit Signs: Control and Setting Locations in Freeway Work Zones

Variable Speed Limit Sign (VSLS) Systems enable speed limits to be changed dynamically in response to traffic conditions so that
traffic incidents can be reduced significantly on freeway work zones. In this paper, we examined how many and where VSLS are to
be placed and the speed limits to be set and proposed a bilevel programming model to perform this decision making operation.
The appropriate speed limits and deployments of VSLS were got by case study, and they were analyzed by a simulation to prove the
empirical features of traffic breakdown at freeway work zones. Then the results of model comparison and simulation evaluation
illustrate that the proposed method outperforms existing models in terms of maximizing information benefit and minimizing
average queue length, total delay, and total stop frequency on the freeway work zone.