Case Study: Safety Improvement for National Highway G109
- Beijing, China
A 96km stretch of the National Highway G109 in Beijing, China was upgraded with several engineering treatments in order to reduce fatalities and serious injuries. Overall the number of casualty crashes decreased by 75% after safety improvement.
The characteristics of the highway included sharp curves, long and steep downgrades, bad sight distance and a dangerous roadside. The design speed of the general environment is 40km/h; however, it is subject to an operating speed of 70-80km/h. Also around 35-56% (depending on location) of the AADT comprises heavy vehicles, indicating high truck volumes.
A number of different treatments/upgrades were performed along the highway, as including
- installation/upgrade of guard rails with wirerope or steel guard rails (where appropriate)
- channelization of intersections
- improved signage and linemarking such as using vibration markings and three-dimensional markings at high-speed segments
- reflective road pavement markers for improved night time delineation
- upgraded roadside drainage/shoulders and friction enhancement of road pavement surface
- attention and consideration for sight distance on curves
- provision of roadside rest stations to cater for fatigued drivers.
The overall cost of the treatment to the National Highway G109 amounted to 1.4 million dollars.