I was able to calculate air pollutant emissions and, in some cases, fuel consumption to demonstrate the impacts of increased congestion in the Providence metropolitan area and to evaluate traffic control methods. In Providence, stop sign maintenance and installation is not well recorded and a stop sign s position is only reevaluated on routine maintenance calls. The city of Providence does not conduct any large-scale comprehensive assessment of traffic flow. When adding a stop sign, I found that local roads experienced an increase of approximately 0.3 to 0.4 kg of CO emissions, 0.1 kg VOC emissions, but not a significant change in NOx emissions. Traffic calming is an attractive alternative to stop signs because it can reduce emissions and fuel consumption, and also slow traffic and therefore decrease risk.
Light synchronization minimizes delay and excess fuel consumption.
The state, in 1994, calculated emissions comparing arterial progression with no progression and found significant emissions reductions in the short and long term with synchronization. Overall, I found that emissions decreased with traffic signal progression, at higher traveling speeds, and with lower VMTs. Arterial progression also proved to have emissions benefits. Stop signs had a negative impact, creating more emissions and increasing fuel consumption. Traffic calming can be a useful alternative to stop signs.