Traffic Model Not Ready for Prime Time

By the Town traffic engineer’s own admission, when the Town-Wide Traffic Model was run on the Aura project on May 3rd, much work remained to be done. The engineer was skeptical whether there would be time and money to add the data that would make the model more accurate in time for the June 16 Council Aura decision. Council member Hongbin Gu asked why an analysis did not
accompany the model demonstration.
Council members are not trained in reading traffic studies, nor are most trained in the sciences. With the exception of Council Member Hongbin Gu, most council members appeared reassured after viewing the little cars running freely on the model concluding there was no longer a traffic problem to be concerned about on Estes Drive. Here are the reasons the model is not yet ready for prime time.
  • Assumed back ground traffic growth factor is 1/2% when usual is 1.5%
  • Unsignalized intersections are not included in the model
  • No data input for impact of three new pedestrian controlled cross walks on Estes
  • Input data for (un)developed properties of Central West parcels used incomplete/incorrect numbers 
  • Important unexplained differences exist between TIA results and model results, e.g. wait time to access Estes from Aura
  • No modeling of Aura resident students impact on Estes traffic since these students will have to cross Estes twice to get to school
  • No Carrboro development impact on Estes was modeled
  • Only averages were included in the model, not taking into account variability in traffic numbers
  • The 2024 Build” model did not have a scenario _without_ a traffic light at Somerset/Estes
  • A 2.5-year projection (to the year 2024) is too short-sighted for the town to take. NCDOT requires a 20-year traffic projection before it approves any new traffic circle
  • Model only projects 2.5 years into the future, likely ignoring long-term negative impact of AURA development