This report assesses the impacts of a prototype of Dynamic Speed Harmonization (SPD-HARM) with Queue Warning (Q-WARN), which are two component applications of the Intelligent Network Flow Optimization (INFLO) bundle. The assessment is based on an extensive analysis of the Prototype using a Vissim simulation model for the US 101 freeway corridor in San Mateo, CA as well as an evaluation of a small-scale demonstration that was conducted in Seattle, WA. Results from the simulation analysis found that the Prototype significantly reduces the magnitudes of the speed drops (shockwaves) between vehicles, even at the 10-percent market penetration level. This is considered to benefit safety by reducing the probability of collisions where free-flowing traffic meets the back of a queue. The trade-off for the improved safety is that the Prototype increases the geographic impact of existing bottlenecks on freeway speeds by expanding the upstream distance that is affected by congestion. (Author/publisher)
Samenvatting