Traffic Impact Study Frequently Asked Questions

 The goal of a TIS is to understand a proposed development's impact on the existing transportation network and to identify short and long-term improvements required to ensure safe and efficient traffic system operation.
As you may know, the City recently purchased the former Atlas Mill site and plans to develop the area to create permanent, public waterfront access and encourage economic development on the site.  Concurrently, Lanzce Douglass, an adjacent developer, recently decided to pursue development of his property as well.  With all this potential development, the City recognized that the adjacent transportation network, specifically, the Northwest Boulevard corridor, has become strained in recent years and wanted to include this area in the study.  Additionally, we wanted to evaluate how proposed connections to Riverstone and modifications to the existing sytem may alleviate existing traffic congestion.
The date came from GPS Location Services data from cell phones.  So, if you use a weather app or check the traffic conditions on your phone, then your location has been tracked.  No personal information is revealed.  In fact, the team receives only aggregated data.  It's not possible to track individual trips or individual vehicles from the data we were given.
From the data, we could clearly understand routes vehicles currently take when traveling to or from Riverstone.  Then, we can make educated assumptions regarding the routes new trips generated by the developments will take.
August is a representative time to count (a typical peak).  September would miss the impact of tourism.  July 4th would be much too high.  The afternoon peak is generally higher than morning peak.  This was confirmed by counts from the City and ITD.  For modeling purposes, not much is gained by counting multiple days because the peak time is used in the model, which doesn't vary considerably from day to day.  For this size of study, we're looking for the network peak, as opposed to various peaks in multiple areas.  This provides the more accurate model data.  Counting at this time as opposed to 24 hours or multiple days also allows us to keep unnecessary costs down.
The study began in July.  We coordinated with the Seltice and I-90 projects to determine the time that would impact the counts the least. 
Finding the best combination of signal timing and cycle length that results in the overall lowest delay in the system. 
Coordinating cycle timing to provide a "green wave" for the major movements.  This allows for a portion of the traffic to make it through more than 1 signal without stopping. 
Technology that allows signals to communicate with each other and adapt to traffic in real-time.  Adaptive signals can adjust the cycle length and the time given to different phases in an attempt to serve the traffic need best.