In Nottingham we have an existing T-junction which has tram movements entering at the top of the T which has the following stages:
Stage 1 – main road in both directions
Stage 2 – main road outbound with RTIGA
Stage 3 – side road
Stage 4 – pedestrians along with trams when needed
When trams are present, because of the alignment, stage 4 and its associated clearance period run for a long time during which the main road outbound is held resulting in congestion. Separately signalling the outbound ahead and right turns so that the ahead movement can run during the tram clearance period has been resisted as fully signalling the right turn would create its own problems.
It has recently been suggested that we try running the outbound ahead movement with an ahead filter arrow during the tram clearance period. This would leave the right turners held whilst the ahead filter was running, able to accept gaps during the full green and with the RTIGA to help them at busy times.
Has anybody else used an ahead filter along with an indicative green arrow in this fashion or have any experience of how waiting right turners respond to this signal arrangement? All thoughts welcome. Thanks.