diamond geezer

 Wednesday, September 02, 2015

The creation of a Cycle Superhighway is a mighty complicated thing. The creators of the original CS2 overlooked this fact and painted a blue stripe down Bow Road, hoping this would do. Thankfully four years on their successors have thought far more carefully about what makes two-wheeled travel safe, and in particular how the street furniture needs to be reorganised to comply.

Bow Road ought to be an easy street to adapt. It's very wide, currently with two lanes of traffic in either direction all the way down. The pavements are unusually broad, often enough for an entire extra lane of traffic if required (and then some). There are few major road junctions between Mile End and the Bow Roundabout, hence not much traffic turning off or on. But the precise layout of the road isn't always simple to adapt, and the scheme's architects have had their work cut out, for several reasons.

Because trees. Trees it turns out are a problem because you can't just go chopping them down to make way for bikes. A few have proven dispensable, however, like the trio of young trees that used to stand outside Thames Magistrates Court near Bow Road station. Engineers decided there was no possible way to insert a bus stop bypass around them, so contractors nipped along in February and chopped them down while nobody was looking, months in advance of any actual construction work taking place.

But these deaths are very much the exceptions. TfL have been extremely careful to ensure that their upgrade plans involve the removal of as few trees as possible, and that's admirable because Bow Road has dozens. Indeed in many places the position of the segregated Cycle Superhighway path appears to have been defined solely by the existing line of trees along the kerb. Rather than cut down a tree, the cycle lane instead eats into what used to be the carriageway, making the road narrower than it was before. In some cases there'd be plenty of room behind the treeline for a cycle lane, but instead a massive width of pavement survives intact, because trees.

And because lampposts. Lampposts it turns out are a problem because you can't just go dismantling them to make way for bikes. Well actually you can, but it's expensive and very time-consuming, so increases the cost and complexity of the upgrade project considerably. The cables to which lampposts are connected generally run under the pavement just inside the kerbline, because that's where lampposts are erected. Change the kerbline and suddenly those cables aren't quite in the right place, and it's such a lot of extra faff. So wherever possible, as with trees, TfL have tried hard to locate the segregated cycle lane without having to move any streetlights.

The lampposts along Bow Road seem to get changed a lot. They've all been replaced at least twice in the last ten years, the most recent new set arising in April 2013. They proved a doddle to change because all you do is embed a new lamppost beside the old, above the cables, and connect the wiring. Shifting lampposts away from the kerb is not a doddle, but is sometimes unavoidable. For example by St Mary's church the bus stop bypass that's currently under construction embraces an existing lamppost, which must now be removed, a project whose timespan is measured in weeks rather than a handful of days. Trees may be sacrosanct but the costs of streetlight rearrangement are sometimes met, because lampposts.

And because pedestrians. Bow Road is a street that lots of pedestrians want to cross, which is why there are lots of pedestrian crossings along the street. But they aren't always located immediately nearby, hence large numbers of jaywalkers choose to cross at intermediate points along the street. In this they're helped by an intermittent central reservation, which allows people to nip across halfway when a suitable gap in the traffic appears... this gap usually created by a pedestrian crossing a few yards up the road. But a central reservation takes up valuable space that CS2 engineers now desperately need, not least because trees and lampposts have restricted outward expansion of the carriageway.

So the central reservations are being dug up to ensure there's still room for double lanes of traffic alongside new segregated cycleways. That's good news for everyone on wheels, but bad news for those on foot whose halfway muster points are being removed. In future what all well-behaved pedestrians should do is walk up the street to the nearest official crossing point, because that'll always be safe, but a significant proportion of Bow Roaders won't be bothered. They'll try to cross anyway, half the road at a time, except in future there'll no longer be a safe perch in the middle of the road on which to wait. Cycle Superhighway architecture is always optimised for perfect behaviour rather than reality, even if that ends up placing more people in danger, because pedestrians.

And because buses. Buses are a nightmare for cyclists to pass because they hug the kerb and frequently pull in and stop. TfL's 'bus stop bypass' design is an excellent solution for bikes, but less so for pedestrians who face another line of traffic between pavement and bus. The bypass island also takes up a large amount of space, certainly a lot more than a typical stop and shelter. The island also has to be gouged out of existing pavement, which doesn't work when that's narrow, or even of average width. It also has to extend the length of two or three buses, in case two or three buses turn up, so swallows up pavement that'll only be sporadically used.

For example at bus stop G (by St Mary's church) only half the pavement is staying as pavement. The remainder of the pavement (where passengers used to wait for a bus) is becoming a cycle lane. The first lane of traffic (where buses stopped) is becoming an island (where passengers will wait for a bus). The second lane of traffic is becoming the first lane of traffic (where buses will stop). And the third lane of traffic is becoming the second lane of traffic, narrowing the width of the carriageway by a third. The net result is that a stopped bus will now leave only one spare lane not two, slowing traffic approaching the roundabout and flyover, because buses.

And because cyclists. Several road junctions along CS2 are being remodelled to provide 100% safe passage for bicycles by keeping them well apart from turning traffic. This is an admirable intention, indeed might even be seen as the main reason for the entire upgrade project. The diggers are out at this week at the foot of Fairfield Road, for example, helping to create a junction that'll allow cyclists to turn safely in any direction rather than the restricted choice officially available at the current time. Traffic chaos this week will eventually be translated into a junction considerably more functional, but also more complex, than that which previously existed.

The creation of non-intersecting paths for cyclists is now deemed essential, but generally requires increased use of traffic lights, and in particular additional phases to feed bikes through. The price of safety is therefore to be paid in additional journey time, because over-engineered junctions always seem to expect participants to wait longer than before. They're also always set up for rush hour traffic, a worst case scenario, whereas if you turn up off-peak they often appear excessive. Hence the new lights on Cycle Superhighway 2 are likely to prove extremely tempting for cyclists to jump, because at times it'll look insane not to, because cyclists.

The creation of a Cycle Superhighway is a mighty complicated thing. TfL's planners have worked smartly within the constraints provided, but have also had to adopt a safety-first approach that sometimes trumps practicality. Many will rightly celebrate next spring when the CS2 upgrade is complete, but the end result can never be optimal for all road users, and there will be long-term losers as well as winners.

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