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Sunday, 13 August 2023

Battersea Bridge: What Can Be Done Quickly

Bridges are often contested spaces simply because they very rarely contribute to dense street networks and as a result, they funnel users to specific points which might be off their general desire lines into situations where trying to manage different users with different energy is a challenge.

It is against such a backdrop that this week, a woman cycling lost her life on Battersea Bridge in London after being hit by a lorry driver. It has been a notorious crossing of the Thames for many years with a terrible safety record. The London Cycling Campaign sets out the litany of failure in its blog.

As is the general case in many UK cities, the layout and classification of the road network has somewhat evolved and in many cases, those designated as A-roads come as a result of that evolution. Battersea Bridge is the A3220, although in a London context, it is not classed as part of the Strategic Road Network (SRN). The specific classification is somewhat moot given the bridge carries some 25,000 motor vehicles a day - sitting here today it is a busy motor traffic route and it is important for bus traffic too. Around 8% of vehicles are either buses or HGVs and this scales to nearly 26,000 if we convert to passenger car units (PCU).

The view over Battersea Bridge from Google Street View. Traffic in both directions and high kerbs with railings between the road and pavement.

From a walking, wheeling and cycling point of view, the bridge has a pair of fairly narrow footways and a carriageway width of about 7.5 metres (at least from Google maps) or a running lane width of about 3.75 metres which puts it in the "sweet" spot of widths which should be avoided for mixing cycle traffic with general traffic (7.2.5 in LTN 1/20 for those interested). It's a width which some drivers think they can still squeeze past someone riding, especially if they are in the gutter and on Battersea Bridge, there are containment kerbs (with barriers behind) protecting what I assume is a weak parapet from vehicle incursion which is not a nice feature to be near on a cycle.

The bridge also carries 3,800 cycle movements a day and so the combination of lane width and volume of buses/ HGVs does immediately create the conditions where people cycling are exposed to risk and at least in terms of absolute numbers, around 25% of collisions involve someone cycling on the bridge. If you throw in the junctions at each end, then this rises to around 28% and in terms of collision risk per daily trip, (and very crudely) a person cycling is about 5 times more likely to be hurt than a motor vehicle occupant (excluding motorcycles). 

It is worth noting that using casualty numbers can be volatile, especially the more serious collisions as the numbers for a section of road are usually low and can drastically change year on year, but we do have a situation which I think is reasonable to conclude that this is a place which is both subjectively and objectively riskier to cycle than it is to drive (or be driven) and not even the prevailing 20mph speed limit is enough to mitigate this.

If we return to LTN 1/20, Figure 4.1 suggests that even at 20mph, we need below 2,000 PCU/ 24hrs and so with 26,000 PCU/ 24hrs we need physical protection. With the width available and keeping two-way motor traffic (which buses at least require) means we have some hard decisions. In the short and medium term, I cannot see there is an infrastructure solution which is going to be politically easy to deliver on Battersea Bridge. "Just ban cars" really isn't a solution here.


400 metres east of Battersea Bridge is Albert Bridge (above). It is quieter at around 10,000 vehicles a day, although that's from estimated flows, but allowing for data quality, it is still going to be way over what most people would feel happy cycling with. However, with a carriageway of maybe just wider than 8 metres, it does give a little more overtaking space, although there are plenty of collisions involving people cycling here. 

My actual interest in this bridge is an historical quirk and that's the fact the bridge is currently subject to a 3 tonne structural weight limit. This is physically enforced by a 6'-6" (2 metres) width restriction, and that's after a strengthening project over a decade ago. My suggestion is that Albert Bridge be made a walking and cycling bridge and potentially (subject to structural engineering input) left accessible for ambulances. Yes, this means motor traffic displacement to Battersea Bridge in the short term, but it's far quicker to roll out than a new walking and cycling bridge or anything clever and radical at Battersea Bridge.

Of course, it's not just about a safe crossing, it's about the network and so such a plan to repurpose Albert Bridge needs to consider the local cycling networks either side. For example, to the south, some filtering could create some quiet routes to the bridge and to the north, maybe a two-way cycle track on Chelsea Embankment on the river-side would provide a really handy way of plugging into the bridge. 

If the network design were clever in how cycle traffic is dealt with through traffic signals on both sides of the river, the loss of time for some trips diverting to Albert Bridge could be offset with priority measures to keep people moving and essentially unravelling the motoring and cycling networks locally.

However, the main problem with all of this (as is usually the case) is political. To the north and owning Albert Bridge, we have the Royal Borough of Kensington & Chelsea which I think it is fair to say has an administration which is actively hostile to cycling. Transport for London owns Battersea Bridge which connects to TfL-managed roads, RBKC streets and to the south, streets managed by the London Borough of Wandsworth which traditionally hasn't been too bothered about cycling (it might be changing slowly).

This means that there are three organisations are intimately connected with varying levels of political backing for cycling which is why the response to collisions on Battersea Bridge has been so stop-start over the years.

For what it's worth, I have had a quick look at trying to design a little bit of a network around Albert Bridge which you can look at here, but essentially we have the following;
  • Filtering the area between Battersea Bridge Road, Prince of Wales Drive and Battersea Park.
  • Albert Bride becomes walking and cycling only.
  • South side of Chelsea Embankment becomes a two-way cycle track.
  • The southern end of Oakley Street (maybe 100 metres) becomes one way for general traffic south with a pair of one-way cycle tracks which crosses Chelsea Embankment to connect to the two-way cycle track and bridge.
Of course, that doesn't deal with the wider network, but it is a start and longer distance routes would converge on the quieter version of Albert Bridge Road which could become a cycle street to reinforce its priority as a key cycle route. Just my thoughts, but I do think this is the kind of thinking we need.

6 comments:

  1. South Side of Chelsea Embankment is already designated for mixed cycle/pedestrian use, but the surface is so poor (uneven flagstones) that very few cyclists use it, despite the often-hostile road traffic.

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    1. Yes, it's a mess and puts walking and cycling in conflict. My suggestion would have people cycling on the road as it would be very quiet.

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    2. Great idea in principle, I suspect that Battersea Bridge Road northbound would take the worst hit from the traffic re-assignment as its pretty much a car park already. What about making PAB one-way northbound and using the remaining width for cycling provision?

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    3. Oh that's a possibility too, but you'd need a decent cycle track to the south of the bridge - the advantage of closing it is to create a quite zone to the south which doesn't need engineering. But yes, an option.

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  2. Information sign board was not provided in the Traffic shead, there is only a sign board with 3ton limit just right front of the bridge. Divers do not have space to manuvor vehicle that is over 3tons.

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    1. There are signs on the roads before anyone would turn off to access the bridge such as here - https://maps.app.goo.gl/DeRwUfvZTmEkQMwq8

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