Case Study: Pune Expressway Road Accident Study - Mumbai, Maharashtra, India

Introduction

The Mumbai – Pune Expressway is an access-controlled highway that connects Mumbai, the commercial capital of India, to the neighbouring city of Pune. Two- and three-wheeled vehicles are not permitted to use the majority of this divided 6-lane roadway which has a speed limit of 80 km/h for much of its 94km length.

During recent years concerns had been raised by the public, motoring clubs and NGO’s regarding the increasing number of traffic collisions occurring along the stretch resulting in fatal and serious injury. However, with some crashes going unreported and those that are reported lacking the necessary detail for effective crash investigation and analysis, the scale of the problem was difficult to establish. Therefore in October 2012 crash investigators from JP Research India (JPRI), working alongside the Maharashtra State Highway Police, began a detailed 12-month crash investigation study along the route in order to identify, record and understand the collision problem.

Methodology

JPRI researchers were informed by the police of any collisions that occurred on the expressway that the police came to know of. During the study period the JPRI accident research team also came upon many collisions on the expressway that had not been reported. These collisions often involved minor injuries or damage only, but occasionally involved serious injuries. Often these crashes were not reported to the police as the vehicle owners preferred not to report the incident. Such events, although not reported to the police, are still important for in-depth crash analysis. Hence, the JPRI accident research team conducted regular inspections of the road length and examined many such non-reported collisions, in addition to those which they were informed of by the police. To determine whether a collision had been reported to the police, JPRI researchers would follow up with the relevant police station up to 2 weeks after the incident.

In- depth crash investigations were conducted in a scientific manner involving detailed examination of the crash scene, crash vehicles and the injuries sustained by the victims. Whenever possible, researchers also interviewed those involved to better understand the collision sequences. The data collected is stored in a database in a format which allows for detailed analysis. Numerous measurements, observations and notes are taken on scientific collision data forms, which are used to build a scientific database called “Road Accident Sampling System – India”, or “RASSI” in short. This scientific database is shared by a consortium of automotive manufacturers who use it for improving vehicle design and developing India- specific safety technologies.

Objectives

During the 12-month study period, 214 collisions were examined and analysed in detail. The study provides an in-depth analysis of the crashes and offers an analysis of the various factors influencing collisions and resulting injuries on the Mumbai – Pune Expressway. The study not only identifies these “contributing factors” but also ranks them based on the number of collisions these factors have influenced. This ranking is to assist policy makers, decision makers and road safety stakeholders in planning cost effective road safety investments using data-driven road safety strategies.

Results

JPRI researchers examined a total of 214 collisions between 7th October 2012 and 31st October 2013. These incidents involved 328 road users (317 vehicles and 11 pedestrians) and resulted in 72 fatal victims and more than 140 serious injury victims. Of the 72 road deaths recorded 48 were car occupants, 19 were truck occupants, there was 1 bus passenger and 4 pedestrians. Run-off-road crashes account for 55% of the crashes followed by collisions between vehicles travelling in the same direction (33%). Vehicles running off the road to the right (29%) were found to have more fatal/serious injury outcomes than vehicles running off the road to the left (20.5%), even though there were more crashes involving vehicles leaving the road to the left.

Recommendations have been made to reduce the severity and likelihood of road crashes along the study route by improving the infrastructure, road user behaviour and vehicle safety standards based on the analysis of all crashes.

Conclusions

Based on one year of crash investigation data for the Mumbai – Pune Expressway, the study concludes the following

• Trucks are highly involved in collisions on the expressway. Of all the vehicles/road users involved in collisions on the expressway, 63% are trucks.
• Cars and trucks are the most affected road user types in collisions on the expressway. Cars constitute 58% of vehicles which had at least one fatal occupant, and 45% of vehicles which had at least one seriously injured occupant. Trucks constitute 30% of vehicles which had at least one fatal occupant, and 37% of vehicles which had at least one seriously injured occupant.
• Run-off-road crashes are the crash type seen most frequently on the expressway, followed by collisions between vehicles travelling in the same direction. Vehicles leaving the carriageway to the left and right sides accounted for 55% of all crashes examined. Collisions with vehicles moving ahead, stopped or moving laterally in the same direction accounted for 33% of all the accidents examined.
• Human factors have the most influence on the occurrence of all crashes, and vehicle factors have the most influence on the occurrence of fatal/ serious injury accidents. Human factors alone (57%) had the highest influence on the occurrence of crashes, followed by the combination of human and infrastructure factors (22.5%) and vehicle factors alone (16.5%). Vehicle factors alone (28%) had the greatest influence on a fatal/serious injury outcome, followed by a combination of human and vehicle factors (21%) and combination of vehicle and infrastructure factors (19%).

For more information download the full report Mumbai – Pune Expressway Road Accident Study

References: JP Research India, RASSI