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Well over 70% of serious injury or fatal collisions happen at major road junctions in the capital each year – a sobering statistic. A major cause of these injuries and deaths is left turning motor traffic, known as ‘left-hooks’ (referring to vehicles crossing a cyclist’s path). Advanced stop lines (ASLs), which were first implemented with the intention of making cyclists more visible and reducing the risk of conflict with motor vehicles, do not eliminate the risk of left hooks. ASLs also can’t eliminate the risk of ‘shunts’ (when a vehicle hits a cyclist from behind), and ‘right-hooks’, which represent the next biggest threats to cyclists. Of course, one of the problems with ASLs is down to driver behaviour – research has suggested between 9 and 54% of motor vehicles encroach on ASLs by at least 25%. But the main problem is that ASLs can’t protect cyclists from being hit by motor vehicles – and they do absolutely nothing to help cyclists arriving when traffic lights are green.
The ‘cycle segregated’ junction, versions of which are illustrated in diagrams below, is one which LCC has championed for two years. We’re now starting to see versions of it in TfL’s plans and we think there’s scope to introduce this type of junction in many more areas of London. It’s safer than the ‘early start’ junction, also seen in TfL plans, which give no protection from left-hooks unless you are at the head of the queue when the lights change. The ‘cycle segregated’ junction is better for pedestrians too, as they get the same amount of ‘green time’ as motor traffic. Transport for London have agreed this model is ‘capacity neutral’ – so shouldn’t negatively impact on journey times.
Variants of the cycle segregated junction exist for all types of junction. We'll be adding more variations to this page in coming weeks, including T junctions with major roads which only require three phases, and a clearer explanation of the two stage right turn.
In Stage 1 of the above diagram, traffic lights are red for traffic turning left and right, and green for traffic — drivers and cyclists — going straight ahead.
East and west-bound traffic can go at the same time and pedestrians can cross at the same time as the ahead traffic.
In phase 2, north and south-bound traffic can go. Result? No risk of traffic turning across the cyclists’ path — therefore no left-hook collisions. And because cyclists and pedestrians get the same amount of ‘green time’ as motor traffic, it’s more efficient for everyone.
In Stage 3, the traffic lights go green for north and south-bound left turns, and east and west-bound right turns. All this traffic can go at the same time.
And finally, in Stage 4, the traffic lights go green for north and south-bound right turns, and east and west-bound left turns.
Crossroads where primary and secondary roads meet
On Stage 1, all north and south ahead traffic goes. At Stage 2, rights and lefts go together, and eastbound cyclists can go.
At Stage 3, southbound rights and lefts go together, and westbound cyclists go ahead. During Stages 2 and 3 east and westbound pedestrians can cross safely at the same time. At Stage 4, east and westbound traffic can go.
This model allows the same number of phases as currently, but gives more time for pedestrians and cycles to cross.
This type of junction can be seen at many locations in London, such as Ludgate Circus.
Duriring Stage 1, all straight ahead east and west bound traffic - vehicles, cycles and pedestrians - can go. Turning motor traffic is held; cyclists turning right do the first stage of a two stage right turn.
In Stage 2, right turning southbound traffic can go - cycles making the second stage of their two stage right turn.
During Stage 3, left turning southbound motor traffic, right turning eastbound traffic (including cycles), and cycles turning left to go west can all go at the same time.
T junctions of major and minor roads
During Stage 1, all east and westbound traffic goes. At Stage 2, right turning traffic goes (cyclists making the second stage of a two stage right turn).
During Stage 3, traffic turning left into the minor road can go, and east and west bound cyclists with a bypass for left turning cycles. At Stage 4, motor traffic turning east or west onto the major road can go.
Harford Street and Mile End Rd is an example of a junction like this:
Left and right turns
Here are the left and right turns in more detail. Cyclists turning right will do so ahead of the pedestrian crossing, so there is no conflict.
For cyclists turning left: if a left filter for cyclists is installed, the flow will usually be fairly low - most cyclists go straight ahead, with only around 20% turning left. A mini-zebra across the cycle lane can be installed to enable pedestrians to cross. If the pedestrian flow is high it is possible to install traffic lights for pedestrians to cross, but in most cases this won't be necessary.