Poor planning causing congestion?

This article was published in 2014, in Newsletter 112.

The first week of the new year, I’ve been somewhat slow and late for work, and thus have been hitting Hills Road about half an hour later than my scheduled 8.15am, namely at 8.45am -the worst time of the morning. So I have been caught up in traffic congestion. However, I can’t help feeling that some of this congestion is caused by poor planning and traffic light phasing, and a total lack of consideration of the number and speed of cycles on Hills Road.

From War Memorial southbound

The first queue I’ve regularly encountered is at the War Memorial, from where Hills Road southbound is ‘full’ all the way over the railway bridge. This means that traffic must back up to the station, presumably causing chaos there. I think I’ve worked out the reason why this queue can be so bad. Several times during the week, waiting in the cycle lane for the Cherry Hinton Road junction, I was halfway up Hills Road railway bridge. That’s how long the queue of cyclists waiting at the lights was! I’ve also noticed the queue of traffic, when the lights go green, moving exceedingly slowly. Friday morning, however, I was at the head of the queue. There was a no. 12 bus behind me. The lights went green, and I got to the by-now-red pedestrian light before the bus. When that went green, the lovely low first gear of my three-speed hub ensured I got a good getaway, as did many of the trail of cyclists behind me. So the bus got stuck, unable to get to the bus stop, presumably holding up a queue of cars behind him. What this meant was that probably fewer than half the number of motor vehicles the traffic planners expect to get over the junction during the green phase actually got over this time. There are many buses.

There are several problems here. The main problem is the position of the bus stops. Having bus stops immediately after a junction, where buses stop and disgorge 30+ passengers while traffic cannot pass the bus, is silly. The problem here is linked to having an institution with 2,000 students, all of whom seem to arrive between 8.30 and 9am, about 50% of them on buses. The dwell time of each bus is massive, and not a product of poor ticketing procedures but of trying to empty an entire bus. It is a pity that, when the area was redeveloped, no-one noticed this flaw and compulsory purchase was not used to allow buses to pull into a bay off the carriageway, which would have helped. However, this would not stop the problem of the bus not being able to get into the bay.

What should help here would be a decent length advanced green light phase for cycles (possibly the length of the green could be tailored to time of day?) where the pedestrian lights were guaranteed not to go red, to allow the bolus of cyclists to get out of the way before buses need to try to stop. The advanced green would also allow time for cyclists wishing to turn right into Purbeck Road firstly to be able to plan ahead and get into the correct road position well ahead of the junction and, secondly, not have a car up behind them, possibly trying to overtake them, while trying to do this manoeuvre. I gather the right turn is a topic of concern amongst Hills Road students and I would be interested to know if they thought this might be a possible solution.

I would also suggest modifying the position of the bus stop to avoid cars getting stuck behind the stationary buses. Rather than move it to where the new bus stops have been painted, by a traffic island which stops cars from overtaking a stationary bus, I consider it should be situated closer to where it has been temporarily located during the building works, roughly outside the Bridge Guest House. There is no traffic island here. Then it should be possible for a car, if not a lorry, to get past a stopped bus even if there is oncoming traffic. If nothing else, there is at least space for more vehicles to get across the green light and queue behind the bus!

Long Road junction

The second queue I’m encountering is at Long Road, which can stretch back to the Perse School. There are often no vehicles in the straight-on lane. They are all stuck behind vehicles wishing to turn right into Long Road. The problem is that at this time in the morning, all the Addenbrooke’s site staff who are being encouraged to cycle to work are filling the Advanced Stop Box (ASB) at the junction to turn across to the shared-use pavement so they can get onto site without cycling around the roundabout, or the same population plus the Long Road Sixth Form College students wishing to turn right onto Long Road. There can be up to twenty cycles in or a bit ahead of the ASB.

Cycles do take time to set off and get across the junction and, again, I suspect fewer than half the number of cars expected by the traffic planners actually manage to turn right in any given green cycle phase, thus leading to a long queue of cars waiting to turn right, blocking the road where it narrows for traffic wishing to go straight on. This is probably because it has simply not occurred to the planners that there are a very large number of cycles turning right here, or somehow they think cycles take up no road space nor traffic light time. A pretty fundamental flaw in my opinion. Again, this is another candidate for advanced greens for cycles, or at least a longer right-turn green phase.

My proposed solutions would inevitably lead to slightly longer dwell times on the other roads approaching each junction. My point is that at the moment one road disproportionately takes the strain, which causes congestion for everyone. Of course if advanced greens were provided, it might encourage more people out of their cars and onto bicycles, which then might reduce congestion for those who really do need to use a car.

I feel both these examples of traffic hold-ups are a result of cycles and especially the weight of cycle traffic I am seeing on Hills Road not being included in traffic flow calculations and the subsequent calculations on the phasing of traffic lights at all. Another case of us being invisible?

Heather Coleman