Wednesday, 17 February 2016

In which I redesign the Old Kent Road

Segregated cycle lanes are popping up all over London at the moment, with what seems like a dozen more in the works once the current crop are complete.

So I wanted to consider the Old Kent Road in Southwark, and wonder: could we fit a cycle lane down here?

Update May 2017: Tfl have proposed exactly this, and the majority of respondents to the initial consultation are in favour.

The background

1) The Old Kent Road is part of the A2. It is a key link between New Cross, Lewisham and parts south-west at one end, and Elephant and Castle, Southwark and the centre of London at the other. There is no easy way around it.

2) The Old Kent Road is wide, it is fast, it is busy, it is not somewhere you ever want a child to cycle.

3) Crossing Southwark from south-east to north-west means crossing the Old Kent Road. There are few cycle-friendly crossings, and safe routes on one side do not link up with safe routes on the other. But there is no safe space to move along the Old Kent Road to reach a crossing or an onward route.

4) Many facilities are on the Old Kent Road, and only the Old Kent Road. In many ways, it is like an out-of-town retail park: dominated by motor traffic, unfriendly to pedestrians, and so home to places expecting you to arrive by car: the Southwark Reuse and Recycling Centre, for example, and B&Q.
But just because we don't own a car, doesn't mean we don't have items to recycle. Likewise, sometimes non-car-owners do DIY. These places are quite inaccessible by public transport, if you don't live along the line of the Old Kent Road, and deeply unpleasant to cycle to. Your choice is the road (suicidal) or the pavement (illegal).

So this is why I want it changed: I want to visit friends on the other side of that road. I want to get to B&Q, and recycle things, and be able to carry put those heavy items on a bike, not my feet. And I want a direct route through the borough to be usable by everyone, including the majority of residents who don't own cars.

Space for cycling?

Firstly, some measurements. Starting at the south-west end, where the New Cross Road becomes the Old Kent Road, I took measurements using Google Maps' measurement tool and aerial footage. So these are not exact numbers, but they're a good place to start.

30.5m (Ilderton Road), 7 lanes
23.5 (Leo Street), 4 lines and a wide painted meridian
26.5 (Gervase St), 5 lanes
23 (Hillbeck Close), 4 lanes
18.7 (Sylan Grove), 4 lanes
19.5 (Devonshire Grove), 4 lanes
28 (Devon Street), 5 lanes
22.5 (Murdock Street), 4 lanes
30m (St James' Road), 6 lanes and a wide planted meridian - outside B&Q
22m (Glengall Road), 4 lanes and a wide painted meridian

So the space between buildings widens and narrows, but is generally over 22.5m wide. Keep that figure in mind.

2.5m pavements

The pavements are 2.5m - 3m wide on each side, in places up to 6m. Presumably, this is so that pedestrians can walk several metres away from fast-moving motor vehicles on the A road. But if there is a cycle track, then pavements wider than 3m should not be necessary; pedestrians will already be well away from the traffic. If pedestrian flows are low, then 2m pavements may be sufficient, but the planned regeneration of the area (including new tube station) presumably aims to change that. Let's say 2.5m for now.

2.5m cycle tracks

If we want to add a one-way cycle track on each side of the road, that would be 2.5m on each side. If we expect only 150 bicycles an hour, then 2m might be ok; but if there was a continuous segregated track that went from New Cross to Elephant and Castle, I think we can assume slightly more in rush hour.

3m traffic lanes

A traffic lane wide enough for a London bus needs to be 3m wide.
Sources: Keeping Buses MovingLCN Design Manual. (Note, 3m is the minimum - tendency for other drivers to stray over the line means more is better if possible, to avoid blockages.)

Adding it up...

So with cycle tracks either side, and pavements, and 2 traffic lanes in each direction, we've used 22m of space. If we add kerbs to separate the cycle tracks from the motor traffic, which would be preferable, let's call it 22.5m.

This is the width of most of the 4-lane sections of the Old Kent Road. We can easily fit in the 5 lane sections without losing a traffic lane, as the road gets much wider where they are. There are a few pinch points where the current number of traffic lanes could not be retained with 10.5m of walking and cycling infrastructure, but I think that a slight narrowing on both sides for a short section could be tolerated, provided that segregation was maintained throughout.

The wrinkles

So it looks like there's enough space here. Now that the Number 1 physical requirement has been met, here are a few of the issues that TfL would have to resolve:


Traffic light timings will need careful thought at currently signalised junctions, to make sure that cycles and cars never cross paths.

Safety at unsignalised junctions needs considering: left-turning drivers may collide with cyclists by approaching from behind, then cutting into their path. These junctions will either need lights, or banned turns, or the pavement and cycle track bending away from the main road, so that the driver is at right angles to pedestrians and cyclists when they cross paths, and travelling slowly.


Lots of London plane trees are planted along the edges of the pavement, and may need relocating to be out of the new cycle tracks. However, Kew Gardens was moving oak trees with a horse and cart in the 1840s, so I think the technology is not out of our reach.

These trees do reduce the effective width of the pavement. However, the A2 is either a main road or an arboretum, not both. If the trees are both too large to fit alongside cycle tracks, and too necessary to remove, then we should lose a lane of motor traffic. If the movement of people and goods is so necessary that we cannot lose transport space, then we definitely need a cycle track - it is a much more efficient use of space than a car lane.


Moving the kerbs means moving the drains. Now we are getting into the "good engineering is expensive" portion, and I am not expert enough to cover all aspects.

I do know that such changes are probably still cheaper than the health costs of a population who are mostly overweight, and can't incorporate exercise into their commute because the roads are too darn scary.

Cycle tracks for Old Kent Road!

3.5km (2 miles) of a direct route between two useful places, possibly without even taking any space away from motor traffic. Why not?


  1. Excellent analysis. Check out
    where Southwark Cyclists are trying to promote OKR segregated cycle lanes as part of the consultation on the Old Kent Road Area Action Plan.

    1. Thanks, and thanks for posting the link. Since writing this post, I've got involved with that. Everyone's now awaiting feedback from Southwark Council on the first round of consultation.