Gilbert Road – a radical proposal



A typical view of Gilbert Road.
Image as described adjacent

Here’s a radical proposal for cycling on Gilbert Road. This street in north Cambridge is a fairly busy through route connecting Milton Road near Mitcham’s Corner to Histon Road.

We would really like to see some hybrid lanes here – wide lanes with a separation from traffic – to replace the useless advisory lanes there now. But it really isn’t wide enough. By laser measure it is about 9.4 metres kerb to kerb along most of its length. So without some lateral thinking the best that’s likely to happen is ‘absolute minimum’ width 1.5 m mandatory lanes down each side. Under the banner of a Demonstration Town project, that’s less than revolutionary and not very satisfactory.

Map showing Gilbert Road

Another constraint is the trees. While there is scope for a little local widening,especially near the junctions, the rest of the road is lined with trees, which no one is likely to be enthusiastic about losing. There’s also a steep camber which makes doing anything near the kerb complicated.

So…

Let’s put bikes down the middle

OK, your mind immediately fills with all the reasons why it can’t be done. But bear with me for a while.

What I have in mind is two 2.9 m or 3 m traffic lanes on either side and 3-and-a-bit metres of flat cycle track between them separated by a fairly shallow kerb up onto the cycleway. To discourage cars using the cycleway to overtake there would need to be posts or other obstacles at strategic intervals.

The reason for doing it this way is that the whole is much greater than the sum of the parts. A two-way 3+ m cycleway is wide; a 1.5 m lane is narrow (and can’t be segregated by a kerb as overtaking would then be impossible).

Current link with Mitcham’s Corner and proposed-cross section.
Image as described adjacent

Image as described adjacent

There is a secondary advantage in this particular location. If the cycleway continued through the Milton Road junction the short distance to Mitcham’s Corner, then it would end in just the right place to join the central crossing of the Corner. This would however need a short stretch of bus lane to be given up. Even if so radical a scheme were accepted, that may be a step too far (though the bus lane is often double parked with cars now).

Image as described adjacent

Junctions

Gilbert Road has traffic lights at both ends and at Carlton Way in the middle. There is also a minor, slightly offset crossroads at the entrance to Chesterton Community College and two other minor side roads with T junctions.

Image as described adjacent

The traffic signals are quite easily dealt with by phases which include the cycleway almost as if it were a separate arm of the junction. But note that turning left onto the cycleway doesn’t need a separate phase – it’s the same as going straight on to start with.

At the side roads the central position of the cycleway would make it much easier to give priority to cycles than it would if they were positioned on the edges. The road can be widened slightly at each junction and put on a raised table so the road rises rather than the cycleway dipping. The main road gives way to the side road so it works a bit like a mini roundabout. The staggered junction is just two of these joined together. See diagram on opposite page.

Yes, it’s a radical solution, but it allows for much more space for bikes in the limited space available.

Q&A

How would I turn right in my car out of my driveway?

You drive across the cycleway, giving way to each stream of traffic in turn (including the cycleway). The kerbs of the cycleway would be angled opposite driveways (which would also allows bikes on and off).

Won’t it mean loss of on-street car parking?

Yes. But so would mandatory cycle lanes or indeed any other scheme to give space to cycles other than an appalling footway conversion to shared use. If this bullet cannot be bitten, we cannot make progress on Gilbert Road at all. Only a couple of houses don’t have driveways.

What about emergency vehicles?

Either they drive on the cycleway or cars hop up onto the cycleway to give way. Obviously it has to be made very clear which. The point is though that they have a way through.

What about deliveries?

There would need to be occasional delivery bays in convenient spaces; the driveways also provide space for a delivery vehicle to pull off the road in most cases and removal vans can back into driveways.

Won’t it be expensive?

Yes. But any solution that isn’t just more of the same old inadequate cycle lanes that frustrate the experienced cyclist without giving more timid cyclists the protection they demand is likely to cost a lot. Quality is the watchword of the Cycle Cambridge project.

Can it be trialled?

I think so. Though the traffic lights have to be properly dealt with, the cycleway could be delineated with railway sleepers or similar and the existing surface used to give it a go.

What about bus stops?

No change. Traffic has to wait behind buses, but that’s safer and adds to the sense of slower traffic caused by the narrower lanes and junction give-ways.

Won’t it mean cyclists crossing the road more?

Not really. Most people will get on at the ends helped by the traffic lights which will feel just like any other junction – better if the phasing is right. For those joining part way, yes, you need to cross, but only a 3 m lane, not the 9 m of two way traffic if lanes were at the edge and which you would have to cross anyway on either the way out or back.

Could children use it?

As a segregated facility, you won’t get anything better that is not completely away from a road. Because it is in the centre with priority, it is much better than a pavement cycleway because it does not cross side roads which is where the danger is (as well as being a much higher quality facility).

David Earl

Cambridge Cycling Campaign feels that innovative ideas are needed. What do you think of this one? Editor