SAE 89-2505 The In-Service Braking Levels of Australian Heavy Vehicles
Abstract:
- A lack of knowledge of driver behaviour and vehicle performance at everyday braking levels has made it difficult to develop Australian Design Rules which achieve a balance of braking between heavy vehicle tractors and trailers under all operating conditions. This paper examines the in-service braking behaviour of heavy vehicle drivers to provide information for use in the development of design rules, which would improve tractor/trailer braking compatibility under routine braking regimes. Results show that while braking is required every 500 m under heavily trafficked urban driving conditions, on roads with high levels of service this can reduce to once every 11 km on average. Under the right road and traffic conditions, heavy vehicles were shown to travel up to 90 kms between brakings. Average braking duration was between 6 and 9 seconds with average deceleration rates of between 0.4 and 0.7 m/s2. These decelerations are considerably less than the 0.25 g accepted as the limit of comfortable passenger car braking, as well as those within which the current Australian Design Rules for truck braking are framed. The average speed change during braking was found to be small for all road types considered, with very few brakings made from very high to low speeds. The constant adjustment of speed to the conditions by drivers appears to pre-empt the need for severe braking. The majority of pedal pressures were found to be below 100 kPa and the rate of pressure rise was modest compared with expectations. Less than 1% of brakings showed the driver to be modulating his braking during the deceleration. The profile of normal braking behaviour developed by the research has allowed recomendations to be made for changes to the Australian Design Rules for heavy vehicle braking and these are currently under industry review.
- Research on car braking under urban conditions Mitunevicius and Nagurnas. 8th International Conference, Transbaltica 2013
- Acceleration-deceleration behaviour of various vehicle types. Bokare and Maurya. World Conference on Transport Research WCTR Shanghai 2016
- A study on driver behaviour during braking on the open road. Kassaagi , Brissart and Popieul. 18th ESV Conference, Paper 340
- Use of intelligent Transport system data to determine driver deceleration and acceleration behaviour. Haas, Inman Dixson and Warren. Transportation Research Record 1899
- Analysis of braking and steering performance in car-following Scenarios. Smith , Najm and Lam, SAE Paper 2003-01-0283
- Analysis of driver’s deceleration behaviour based on naturalistic driving data. Li, Li, Yao, Xu and Chen. Traffic Injury Prevention v21, 2020 Issue 1
- Adaptations in driver deceleration behaviour with automatic incident detection: a naturalistic driving study. Varotto, Jansen, Bijleveld and van Nes. Traqnsportation Research Part F. v78 pp 164-179
- Analyzing and modelling drivers deceleration behaviour from normal driving. Deligianni, Quddus, Morris, Anvuur, Reed. TRR Paper 17-03255, 2017, 288368005.pdf (core.ac.uk)
- Use of naturalistic driving study data to determine right turn driver deceleration behaviour at signalized intersections. Xu, Wu, TRB 97th Annual Meeting 2018
- Exploratory analysis of deceleration rates in urban corridors using SHRP-2 data. Lindheimer, Avelar, Dastgirl, Brewer and Dixon. TRB 97th annual meeting