Some thoughts on the Lambeth Bridge Roundabout

The Cycling Embassy have published their response to Transport for London’s consultation on their proposed improvements to the roundabout at the northern end of Lambeth Bridge, as seen below.

The Embassy response essentially mirrors the suggestions of the Dutch Cycling Embassy, and Rachel Aldred. It argues that providing for two categories of cyclists on this roundabout (by allowing some cyclists to use the pavement, while recognising that many will continue to use the roundabout) results in sub-optimal provision for both groups.

Cyclists on the pavement are brought into conflict with pedestrians, and have the unenviable task of trying to cycle across zebra crossings, with dubious priority. They also have to leave and re-enter the carriageway at dangerous places, and at sharp angles; for instance –

Meanwhile those cyclists who continue to use the carriageway will find that this scheme has actually made things worse for them. The conflict points on exit and entry remain; for instance, from Millbank, the cycle lane and vehicle lane open out into two vehicle lanes, and onto Millbank, two lanes quickly merge into one –

At these locations this conflict will be kept, and the carriageway will be narrowed by the pavement build-outs, constructed over the existing hatched areas, and widening of the existing islands, like the one seen in the picture above.

A bold solution would be to redesign the roundabout, providing one treatment that is suitable for all cyclists to use; namely a Dutch-style roundabout, with a wide segregated track around the perimeter. Indeed, this is precisely what the Dutch Cycling Embassy recommend, having visited the site last week.

Courtesy of Royal Haskoning (pdf)

It would look like this –

Courtesy of London Cycling Campaign

The tracks would run, with priority, across the proposed raised tables for the existing zebra crossings. Department for Transport regulations currently permit priority for cycle tracks, on such a raised table. Strictly, the zebra would have to be separated from the cycle track by two zig-zags, although there is surely room for experimentation in the separation, bringing the two closer together.

The one outstanding issue is, of course, that this roundabout requires a single vehicle lane on entry and exit, and around the roundabout; the existing roundabout has two lanes on entry and exit, as well as around it, and this arrangement is maintained under the proposed improvements.

Clearly a reduction in the number of lanes on entry and exit would affect the motor vehicle capacity of the roundabout. However it is worth noting that all the roads approaching the roundabout are single carriageway, and that on several of the arms, the two lane queuing space is particularly short. Indeed on some of the arms, motor traffic seems to enter in single file already.

Lambeth Bridge approach

Horseferry Road approach

I also took this ten minute video of the entry from Millbank (you can also the entry from the bridge in the background, to the right).

This was at rush hour. If you don’t want to sit through the entire video, I can tell you that only on a handful of occasions did motor vehicles enter the roundabout side by side; the great majority of vehicles entered in single file, from both the visible arms. So there is already some scope for reduction of the number of lanes on entry and exit, to make the roundabout safer, and to create space for a cycle track.

We should also consider that sensible transport policy in a major city should involve trying to get people out of cars and onto modes of transport that use space more efficiently, and that aren’t as polluting. Creating safe ways of negotiating roundabouts like this one are a sensible way of enabling bicycle use, instead of car use. Charlie Holland has taken a look at the bridge, and discovered that there is a huge amount of capacity here, if we consider how many of the private vehicles are single occupancy. It’s high time that sane modes of inner-city transport were prioritised, at the expense of inappropriate ones, rather than the other way around.

And, of course, Boris – who Transport for London answer to – has only this year pledged his support to Go Dutch, which demands that he

Make sure all planned developments on the main roads that they controls are complete to Go Dutch standards, especially junctions.

‘Going Dutch’ means high-quality, wide segregated tracks around the perimeter of the roundabout. It doesn’t mean putting cyclists on the pavement.

The consultation is still open today – responses can be submitted here