Using weigh-in-motion data to predict the likelihood of exceeding the capacity of a road safety barrier

Andrew Burbridge
Rod J Troutbeck

Run-off road and head-on crashes together constitute around 38% of all casualty crashes and a higher proportion (closer to 50%) of all fatality crashes in Queensland, Australia. These statistics are a fair reflection of the national condition. Vehicles leaving the travelled way are a significant contributor to Australian road trauma. The Australian National Road Safety Strategy proposes a number of infrastructure treatments for tackling these two crash types, including the use of an appropriate road safety barrier. Road authorities deploy longitudinal road safety barriers primarily to prevent errant vehicles from impacting with hazardous roadside objects that could cause an adverse outcome for either the occupants of the errant vehicle or third parties. However, road safety barriers are not equal and are differentiated in the first instance by their capacity to contain impacts of different speed, mass and angle of incidence. While roadway departure speeds and departure angles are well-addressed in contemporary academic literature and methodologies for road safety barrier selection, the mass-distribution of the in-service vehicle fleet is less well represented. This study proposes the use of data obtained from weigh-in-motion technology to represent the mass-frequency distribution of the in-service vehicle fleet. Combined with roadway departures conditions reported by others, a methodology is presented for calculating the likelihood of vehicle-barrier impact exceeding the road safety barrier capacities prescribed by the predominant global test protocols for road safety barriers. The methodology is used to consider how different roadway configurations and traffic compositions might influence the likelihood of barrier capacity exceedance. The results from modelling of various scenarios are reported. The results suggest that the relative likelihood of barrier capacity exceedance varies as a function of cross-sectional geometry as well as traffic composition, so suggesting that a “one-size fits all” approach to road safety barrier selection is not appropriate.



International Conference on Electric Road Systems starts today

Electric Road Systems (ERS) is a relatively new concept with many initiatives on the way. To learn from each other and stimulate new collaborations the Swedish Research and Innovation Platform for Electric Roads arranged the first international conference...


Same survey of road users’ attitudes in 50 countries

At the Road Safety on Five Continents Conference, RS5C, one entire session presented a large survey of road users' attitudes in 38 countries. Results show large differences between countries in many areas, both regarding behavior and attitudes. A new survey...


Good results with alcohol interlock program according to Swedish study

An alcohol interlock program makes it possible for drink driving offenders to continue their everyday lives. In a Swedish study most of the participants were satisfied with the program and experienced improved health. They also reported drinking alcohol more...


Traffic safety in the spotlight

Today the Conference Road Safety on Five Continents (RS5C) opened in Jeju Island, South Korea. More than 220 participators have come from all over the world to present findings and learn about traffic safety. Dr. Young Tae Kim, Secretary-General of the...


VTI will develop simulators for ambulance staff

VTI has initiated a pilot study for paramedics with the Centre for Teaching & Research in Disaster Medicine and Traumatology and Linköping University. The aim is to give ambulance staff the opportunity to practice critical medical tasks in a moving vehicle in...


Unique electrified road opens in Sweden

The world’s first electrified road recharging the batteries of cars and trucks while driving opened in Sweden. The Swedish Minister for Infrastructure, Tomas Eneroth, was at the formal inauguration of the electrified road on April 11, 2018. VTI is one of 22...