Junction experiments

This article was published in 2011, in Newsletter 97.



We had an item on the Cycle Cambridge ‘to do’ list three years ago that was all about trying out some radical changes to junctions. It was there at our request, and I don’t think anyone at the county council really took it seriously. Inevitably it was one of the items that fell off the end when Cycling England funding dried up.

It should still be on wish lists, though. There are numerous examples across Europe where interesting innovations have been made to junction design to improve matters for cyclists, but we always seem really reluctant to try out anything different here. Just look at the ballyhoo over the fact that a junction in central London was remodelled to allow – gasp – pedestrians to cross diagonally!

Here are a few ideas, mostly not original, but largely unheard of in this country.

Traffic signalling

Eye-level lights (left) and left filter lights (right): two traffic signalling options which would improve junctions for cyclists. Examples shown are from Århus and Amsterdam.
Image as described adjacent Image as described adjacent

Use smaller eye-level traffic lights for cyclists. Commonplace in France even for the lead motorist, these would be so much more convenient, especially with the trend not to have lights on the other side of a junction. Surely they’d be cheaper too?

Have left filter lights for cyclists. Commonplace in Germany. We have straight on cycle filters in Cambridge, but there is no approved design for left turn green for cyclists. (While a general left turn exemption for cyclists at lights might be nice, it would be a serious problem for pedestrians and make it impossible to operate a pedestrian green phase.) The most useful location for this would be turning left into Downing Street from St Andrew’s Street. Here pedestrians naturally cross with a red light against them at exactly the time cyclists are currently allowed to turn – because that is when the traffic coming out of Downing Street stops. It would make a lot more sense for cyclists to be able to turn into Downing Street while traffic was emerging from it, and it is only really the lack of satisfactory signs to allow this that makes it not possible.

Three-way junctions

An example of the kind of three-way junction which could be implemented in locations such as Hills Road at Station Road.
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Cambridge has quite a few T-junctions controlled by traffic lights or mini-roundabouts. Consider, for example, Hills Road at Station Road and Trumpington Road at Fen Causeway. With suitable lane markings, there really is no reason why cyclists need to stop on the ‘cross-bar’ of the T. Yes, there may be another cyclist coming from the right, but this can be provided for by a Give Way on the main road. In practice, this is, of course, what happens illegally already at all locations of this kind. Other cyclists seem surprised if you stop at the northbound red light on Hills Road at Station Road. One cause for concern is the extent to which large vehicles turning out of Station Road intrude on the lane at that junction and a more serious impediment to lazy turning might be useful.

Other examples include:

  • St Andrew’s Street southbound at Downing Street
  • Trumpington Street northbound at Lensfield Road
  • Madingley Road eastbound at Grange Road.

Cycle-pedestrian all directions at once

Include a phase in some traffic-signalled crossroads where cyclists and pedestrians get an ‘all directions free for all’, including crossing diagonally. This has been tried successfully in the Netherlands. No doubt an objection would be that you can’t have a green light for pedestrians if traffic (i.e. cycles) can be passing at the same time. But that’s what this is all about – learning how to signpost such things.

There would also be howls of protest about imagined detriment to pedestrians. However, you only have to go to the junction of Arbury Road and Union Lane with Milton Road to see this working (illegally again) in practice. Here the cycleway crosses over and the lights are agonisingly slow and the approach roads are narrow and busy, so cyclists use the pedestrian phase in large numbers both to cross with the pedestrians and to cross diagonally. And guess what? It works perfectly well.

I had originally thought the junction of Queen’s Road / Newnham Road / Sidgwick Street / Silver Street would be a good place to try this, but actually the Milton Road example would be much better – formalising the status quo in effect.

External lanes around roundabouts

This has been tried widely in Europe both with simple lanes across the entrances and exits, and cycleways which are separate and cross the exits with priority over motor vehicles. It has even been tried half-heartedly here in Cambridge long ago, at the big roundabout by Sainsbury’s. Maybe it is time to try this again more seriously.

External lanes around roundabouts like this one would be worth trying again in Cambridge.
Image as described adjacent

One-way major roads

This sounds like an impossibly radical suggestion, to make major roads into the city one way. But it was in fact one of the ideas to reduce traffic and free space for buses and cycles that was a key plank of the ‘congestion charging’ scheme. The actual traffic management proposals were drowned out by the screams of agony over the charging proposals.

Reverse priorities

At many junctions the dominant pattern of cycle flow is quite different from that of other vehicles. Where cycle flows are particularly high and other vehicle flows aren’t that high, there is a strong case for not disadvantaging the cyclists just because they are on what would otherwise be the ‘minor’ road. A good example is at the western end of the contraflow where cyclists find it particularly hard to cross from Pembroke Street into Mill Lane or turn right into Trumpington Street. Trumpington Street could become the ‘minor’ road giving way to Pembroke Street and Mill Lane. (Other locations with very high cycle flows where this might apply usually have signals to make them more equitable.)

David Earl