Advanced Driver-Assistance Systems for City Bus Applications 2020-01-1208
In 2018 there were over 1,700 fatalities on Great Britain roads, with over 25,000 people seriously injured. With vehicle miles increasing each year it is important that there is improved on-road safety, both for passenger cars and for public transport. Nowadays, advanced driver-assistance systems (ADAS) are widely utilized, with the EU Commission mandating ADAS such as autonomous emergency braking (AEB), lane-keeping assistance and reversing cameras on all new cars from 2021. Transport for London have introduced the Bus Safety Standard, within which is the requirement for ADAS systems, many of which are due to become mandatory from 2021.
This study uses statistical analysis of bus accidents that have occurred across Great Britain in order to determine which ADAS technologies may result in the largest reduction of potential bus accidents. It discusses the technologies available for bus applications and compares those that are appropriate with those utilized on cars.
Police reported traffic accident data for Great Britain, over the period 2011-2017, was filtered down to over 30,000 injuries caused by accidents involving buses. From this data it was found that 75% of pedestrian fatalities occurred due to collisions with a front of bus impact. For bus occupant serious/fatal casualties, 80% occurred in non-collision situations. These results highlight the need for forward collision warning systems on city buses, however, careful consideration is needed for autonomous braking on public transport. The deceleration rates experienced during bus emergency braking events, obtained from test track data as well as drive cycle analysis of city bus operations in London, were found to be above the safe braking limits stated in literature for unrestrained seated and standing passengers. Although AEB is widely utilized in cars, autonomous retarder use may be more appropriate for actively decelerating city buses, as shown by testing conducted in this work.
Luke Blades, Roy Douglas, Juliana Early, Chun Yi Lo, Robert Best
Queen's University Belfast, Kowloon Motor Bus Co., Wrightbus