Analysis of design and implementation standards for coordinated traffic signal systems
The National Transportation Operations Coalition (NTOC) gave the overall traffic signal timing practice in the U.S. a grade of “D” for the year 2007. Furthermore, signal operations in coordinated systems receive a grade of “D” as well. Although there are many factors influencing the poor score, the disconnect between the traffic signal design process and their implementation is a major obstacle. This thesis proposes using the existing standards of the Universal Traffic Data Format (UTDF) and the National Transportation Communications for ITS Protocol (NTCIP) to improve the practice of implementing Actuated Coordinated signal systems. To achieve this, the two standards are compared to identify elements that: (i) map identically, (ii) need simple translation, (iii) can be determined using engineering translation, and (iv), items that have no connection. It was observed that only 47% of the basic parameters, either identically or with simple translation, are able to be mapped for UTDF to NTCIP. The differences between these standards illustrate the lack of integration between the practice of traffic signal design and traffic signal operation. Although this is a situation where consultant engineering services can address the problem, this thesis suggests that current practices too often lead to sub-optimal implementation of good signal timing designs. Linking signal timing designs and field deployment by requiring signal timing plans that map entirely from design to an NTCIP compliant controller is a significant step in addressing the current discontinuities and providing overall support to improving signal timing in the U.S.^
Darcy M. Bullock, Purdue University.