Safety audit of Yamuna Expressway
Geetam Tiwari, Kalaga Ramchandra Rao, K.N. Jha and Sudipto Mukherjee
This report presents findings of a Road safety audit (RSA) of Yamuna Expressway (YE) conducted in December-January 2018-19 at the request of Yamuna Expressway Authority.
YE is a high speed road connecting Greater Noida to Agra in the State of Uttar Pradesh. The expressway has been in operation August 2012. It is a 165.537 km long stretch with six lane divided carriageway and extendable to 8 lanes throughout the corridor with a 6 m wide median.
The first objective of the audit is to identify geometric deficiencies in the YE alignment including the entry exit ramps, toll booths and all facilities along the corridor with respect to traffic safety and suggest corrective measures. Second objective is to identify deficiencies in signage marking and road side barriers on the YE corridor with respect to traffic safety and suggest corrective measures. Third objective is to identify high crash locations based on last six year road traffic crash (RTC) data along the corridor and suggest measures to reduce RTC risk on these locations. Fourth objective is to suggest measures to improve speed compliance along the corridor.
RTC data since 2012 was shared by the YE authority. Hazardous crash locations were identified after plotting the RTC data on a GIS base. The average annual crash rate per km was found out to be 3.39. Fourty one percent fatal and thirty three percent non-fatal crashes involved rear end collision. Twenty three percent fatal and fourty four percent non-fatal crashes involved hitting median/guard rail or overturned. Fourteen locations were identified has hazardous locations based on GIS hot spot analysis. Three sets of checklists conforming to the IRC standards were prepared for the entry exit ramps, linear sections and toll booths. The audit was divided into day time audit and night time audit. All entry/exit ramps, toll booths and 42 specific location along the linear sections were audited with the help of the check list.
The audit the entry exit ramps showed missing markings, inadequate speed control devices. The installation of the guardrails is incorrect. Crash cushions are missing at the exit ramps. The acceleration and deceleration lane markings are inadequate. The transitions of w beam guardrail and concrete parapet wall is incorrect. Chevron markings is marked wrong at most of the locations. Road studs are not as per standards. Non-reflective markings have also been observed at some of the locations. There are not enough advance warning signs on the expressway to warn the driver of the upcoming changes in the geometry of the expressway. Wrong side driving has been observed at the entry and exit ramps. Bus commuters wait often near the entry ramp and interchange loops. Along linear sections, raised median is not as per the current standards. Many sign boards are on the shoulder, within the run-off zone, guard rail installation is incorrect at many locations. There are multiple problems concerning road signs on the expressway. First, there are no regulatory and warning signs, only informatory and advertisement signs are present. Second, most of the signpost is on the shoulder itself and some which are not on the shoulder is too close to the crash barrier. Third, there are multiple nonstandard signs present on the expressway. Finally, the retro-reflectivity of the standard informatory signs present on the expressway is good but those of the nonstandard sign are very poor. There are problems in the case of crash barrier on the shoulder. First, the height of the crash barrier is not standard and fluctuate between 550 mm to 700 mm. Second, all the crash barrier for the gantry poles are incorrect. Third, there is no transition treatment on the crash barrier anywhere on the expressway. Fourth, the damaged crash barrier is left unrepaired. Fifth, the place where crash barrier meets bridge parapet, the drain is outside of the crash barrier. Sixth, at places, there are steep slopes behind the crash barrier without the adequate space for deflection of the barrier. Seventh, there do exit retro-reflective tapes on the crash barrier but they are not present on the bridge parapet wall making them quite dangerous in the nighttime. Finally, the retro-reflective tapes are only present on the post of the crash barrier; they should also be present on the w-beam of the barrier.
The recommendations are based on the best practices available internationally for solving the safety issue on the high speed roads. Recommendations are made separately for entry and exit ramps, linear sections and toll plaza sections. Some of the important recommendations are:
Installation of rumble strips at the entry and exit ramps.
Installation of crash attenuators at the exit ramps.
Additional signage (distance bar markings) before the exit ramps.
Audible shoulder marking throughout the corridor.
Remove all sign posts from the shoulders. There should be no posts on the hard or soft shoulder.
Shoulder guard rail to be re-installed as per the standard specification.
Raised median to be replaced with flush median and central guard rail as per the standard.
The fatal and non-fatal crash investigation data from the period 2012 -2018 as reported indicates that:
Twenty three percent of fatal crashes and 53 percent of non-fatal crashes included median impacts, hit guard rail and rollover crashes. Therefore s significant number of these can be controlled/prevented by replacing the present guardrails and raised medians by guard rails that satisfy international best practices fro access controlled expressway where traffic includes heavy buses and trucks.
Fourty one percent of fatal and 33 percent of non-fatal crashes were recorded as rear-end impacts. At the same time for 21% of both fatal and non-fatal crashes speeding has been recorded as a reason for 48 and 42 percent respectively sleep or fatigue has been recorded as a reason. While it is very difficult to ascertain any of these as definitive causes with very detailed professional investigations, it does become important that serious attention is given to reduction in these and other crashes.
While design improvements in road markings and other design features would be most important in crash reduction, it is also important to strengthen the enforcement activities involving the following measures:
Speed control
(i) Average speed to be calculated between toll booths automatically, and violators fined.
(ii) Presence of speed cameras to be advertised repeatedly by signs on the road.
(iii) Checks on speeding and zig-zagging by stationary patrols along the Expressway at different locations selected randomly every day.
Strict checking of vehicles stopping on the expressway for reasons other than emergencies.
Random alcohol checks at toll booths every day.
The above enforcement measures will need to be done by UP Police and a contarct may have to be arranged.
The findings of this audit are applicable to the safety related issues of any high speed road existing in the country. Indeed, the lessons learnt from this audit must be a learning for future development of the highways and to mitigate the crashes problem in the existing highways. One of the important learning from this audit is that mere conforming to standards and specification does not guarantee safety.