With all crossings there is a compromise between the delays to motorists and pedestrians / cyclists.
At present the crossings react fairly quickly to pedestrians. At the busy times, traffic is very slow moving on Bridge Rd, and in particular northbound traffic is often unable to move because of the queue in front of it. In these circumstances there is no point in holding pedestrians, so the signals change in their favour so that they can cross.
Even when the roads are quieter, northbound traffic stopped at a crossing will often catch up with the back of a queue further along Bridge Road, so the overall journey time, or delay to motorists, is generally unaffected by stopping at the crossing.
It is anticipated that when the widening scheme is complete the pedestrians crossings will operate in a similar manner to the way they do at present. Southbound delays to motorist will be reduced as traffic will be moving in two lanes, northbound the delays to motorists will be unaffected, as will delays to pedestrians.