Tower Bridge

Sorry, it's a London-centric post this week, but there's application for many situations. The iconic Tower Bridge is closing for essential maintenance for three months and it presents an opportunity.

The venerable structure is being closed between 1st October and 30th December for major planned maintenance and so drivers and cyclists will be diverted elsewhere and other than a few weekends, it will be available for pedestrian use only (a ferry is planned for full closure days).

Tower Bridge and its approach roads are the A100 and form part of a rough circle of A roads around The City which also run in some of the other adjacent boroughs. Some of the A roads around the area and indeed within the area are A roads in classification, rather than design in that they were never designed to take high levels of motor traffic, its a network which evolved.

Southern approach to Tower Bridge.

Tower Bridge is often held up as being strategically important as the next crossing of the Thames (for motor traffic) is the Rotherhithe Tunnel some 2km east and then we have the Blackwall Tunnel a further 3km east of that (as the crow flies). Tower bridge carries all classes of traffic up to 18 tonnes, including 3 bus routes, and so it is pretty important locally with delivery lorries, taxis and private vehicles. There is also a 20mph speed limit which along with the weight limit, helps manage the loading on the historic structure; both are camera-enforced.

From a walking point of view, the footways are reasonably wide, but they can often get busy with tourists which is what one would suspect. From a cycling point of view, there is no infrastructure and what you tend to find is that drivers often try and overtake you on the approach roads before the main span of the bridge which is much narrower - it's awful as are the approach roads themselves! On the north side, the east-west CS superhighway passes within 500 metres.

The Google car captures the conditions for cycling!

Traffic-wise, we have a Department for Transport count point on the A100, just south of the bridge;

Since the year 2000, there has been an almost 40% reduction in motor traffic crossing Tower Bridge. There has been some fluctuations and in 2015, there is a hint that traffic might be growing again. LGVs and HGVs have dropped by 22% and 26% over the same period, with motorcycle use dropping about 40%. Cycle traffic has grown 140% in the same period and as a percentage of all traffic, cycling has gone from less than 3% to 20% which is astonishing given how awful it is to ride there. Bus/ coach traffic has stayed fairly consistent.

The closure will affect motor traffic and cycle traffic with separate diversions for people travelling northbound and southbound. Northbound will be via London Bridge some 900m to the west and southbound traffic will be via Southwark Bridge which is another 450m to the west. There are also other restrictions designed to make the diversions work.

It's an interesting time of the year for the closure as it will be through the Autumn and into the run up to Christmas which is a time when traffic levels tend to be at the highest; the Summer holidays would have been more usual, although we only have 6-weeks then. Also, bridge works taken place at this time might have more weather interference, but the decisions will have been taken by The City which manages the bridge and in turn they may well have had to coordinate with other major works in the area.

So, what is the opportunity? It would be a perfect time to get some traffic monitoring out on the road network in the surrounding area to see what the impact on traffic flows and congestion is. This could provide data to enable a discussion to take place on how traffic is managed in the future. Unlike a good wine, bridges don't improve with age and they need increasing amounts of investment to maintain any given level of service. Tower Bridge is Grade I listed and 122 years old and is having its timber decking refurbished for the first time since 1970. 

The discussion we should be having is whether or not we should continue to allow so much motor traffic to use Tower Bridge. It would be simple to use a traffic management order to restrict the bridge to buses, taxis and cycles (with exemption for emergency vehicles of course). From a cycling point of view, it would still mean mixing with traffic and there would be no gains for people walking.

To go further, we could run a contraflow over the bridge controlled by traffic signals - there is stacking space either side. This would free up space within which cycle tracks could be provided;

OK, the dimensions are a bit rough (I've taken from Google), but it shows how the space could be rebalanced to enable cycling. Away from the bridge, there is plenty of space for cycle tracks and wider footways. This type of thinking could take place on any bridge which is showing its age and as ever, we are dealing with the politics of space.