bike - Advanced stop line
Photograph by Noah Scalinon Flickr.
The main goal is to prevent collisions between motorists turning right and cyclists going straight. The reasoning is that this puts cyclists bike Black Label Bike Club clearly into the view of HGV (heavy goods vehicles) drivers, who have a blind spot up to 4 m directly in front bike of the cab.
An advanced stop line (ASL) is a road marking at signalised road junctions allowing certain types of vehicle a head start when the traffic signal changes from red to green. A Bike Box in Portland, Oregon Most commonly associated with bicycles, they may also be provided for bike buses and motorcycles. It s all about visibility and awareness.
Success will depend on cars not blocking the cycle lane or encroaching on the reservoir, and on signal timings which ensure that cyclists are not frequently stopped. . This arrangement theoretically allows cyclists to play to their strengths by bike regularising the practice of filtering to the top of queuing traffic during the red phase at traffic lights.
At a red light, cyclists are more visible to motorists by being in front of them. According to an OECD review, ASLs are also advocated as way of improving pedestrian bike safety at crossings by increasing the separation between crossing pedestrians and waiting motor vehicles. Although waiting cyclists might be safer out in front of HGVs, concerns have been expressed about nearside cycle lanes approaching such intersections may encourage cyclists to creep up on the inside of turning HGVs.
Cyclists turning to the offside (ie right in the UK and Ireland, left in USA etc) are able to take up a proper turning position. In Bristol they have been used on the approach to a signalised roundabout.
Straight-on cyclists can adopt and maintain a prominent position for transiting the junction safely within the main traffic stream. There are two parallel stop lines at the intersection, the first one at which all traffic except that for which the facility is provided must stop, and a second one nearer the intersection to which only specified vehicles may proceed.
An ASL will also help reduce the exposure of such cyclists at junctions with nearside (ie left in the UK and Ireland, right in USA etc) filter lights by providing a place for cyclists to wait while traffic passes on the inside. A similar consideration arises where a free turn to the nearside is permitted (called right-turn-on-red in the US). Based on Danish research, it is argued that an ASL should have the general stop line 5 m back from the main traffic signal.
The area between the stop lines is the reservoir or box . Traffic regulations in some countries (eg UK and Ireland) may require a cycle lane to give cyclists a legal way of bypassing the first stop line.
A separate set of traffic signals may be provided for the specified traffic, but all vehicles usually use the same signals. ASLs for cyclists are generally used in conjunction with some form of cycle lane for filtering cycle traffic. At a green light, the green bike lane through the intersection reminds motorists and cyclists to watch for each other. A leaflet produced by the UK Department for Transport notes: ASLs have been used successfully at sites with motor vehicle flows up to 1000 vehicles per hour, and with two-lane approaches.
