Safety Evaluation at Urban Intersections Using Surrogate Measures

This paper aims to clarify the concept of surrogate measures of safety, summarizes the past research in the area and to investigate how simulation can be used in assessing the safety of intersections and midblock on the selected Project Corridor. In this context, four-lane divided carriageway connecting Gurugram with Faridabad and thus spanning a length of km 24.3 has been selected as the study stretch. For the above road corridor, traffic safety measures have been carried out based on the observed road crash data using different types of statistical approaches, mainly before–after comparisons of observed data, and forecasting studies based on road safety audits. This is primarily carried out on the assumption that there is direct correlation between the degree of safety on a road and the number of road crashes that occur there. Even though road crash data is a true representation of safety, its use in safety studies has many limitations. There are many other techniques which can be used for traffic safety evaluation in advance before the accidents occurs. These techniques are called traffic surrogate models. The word ‘surrogate’ means ‘substitute’ or ‘replacement’ which implies that by using surrogate measures to determine traffic safety as another factor to represent traffic safety. The surrogate measure model has been attempted on Gurugram–Faridabad road which is one of the major links between the two cities. It is regularly used by thousands of motorists commuting between Gurgaon and Faridabad. About 279 road crashes were reported on the study stretch during the last seven years which accounted for 165 road deaths and 250 persons injured.