Thursday, July 21, 2011

An analysis (of traffic or anything else) is only as good as its data: Part 1 
          
Heather is lead researcher on Cherenzia's traffic analysis. Her post on trip generation will appear shortly. 


           On December 15, 2010, Bryant Associates of Lincoln, Rhode Island, submitted a “Preliminary Traffic Analysis” to Cherenzia Excavation, Ltd. A traffic analysis generally has three sections: a study of average daily traffic counts in an area; a study of the number of trips generated by residents of a new development; a distribution report that details the choices of routes to be taken by residents.
        It is standard procedure to use traffic data generated by the Connecticut Department of Transportation in the first section of such a report. Average Daily Traffic (ADT) counts throughout the state are available at The Traffic Count Locator on the DOT website. 
        Bryant Associates chose two sites in the Loop to capture neighborhood traffic counts.  The first is at the corner of Greenhaven just south of Sunrise.  It shows Average Daily Traffic as 400 vehicles. The second site is on Mary Hall Road close to the intersection of River Road. The ADT there is 1,200 vehicles. (At another level of DOT detail, these counts appear without rounding:  407 and 1,286.)
These sites seem to be odd choices.  The Greenhaven site is a half mile south of our Mary Hall Road intersection, a corner which will carry a lot more cars if this proposed development is approved.  A count at Sunrise does not correctly describe the amount of traffic flowing in and out of our neighborhood. The second site is also an oddity.  It counts the traffic on Mary Hall rather than the more important road into which it flows, River Road.