Thursday 30 July 2015

Big Blue Wobbly Thing*

I happened to be at Whitechapel in East London earlier this week which gave me the opportunity to have a quick look at the new layout for Cycle Superhighway 2 (the CS2 remix if you will).

I'll be honest, I am going to be critical and it pains me to be like this because the original CS2 was comprised of an awful lot of blue painted stripes in running lanes, with not even a cycle lane to provide any clear space. TfL is calling the work an upgrade, but the old layout did little other provide a wayfinding route and so an upgrade is not difficult.

Don't get me wrong, what is going in is starting to address the protection issue. It is very much a work in progress and there is a long way to go before the scheme is finished so I can only give the briefest of comments on the work so far.

Looking northeast with Greatorex Street on the left
I was on site for a while on Monday morning, but I didn't stop on the way home, so this post is only a little snapshot! I was wandering around on the northwest side of the A11 Whitechapel Road near Greatorex Street and before I go on, it is worth just reminding ourselves on the old non-infrastructure looked like - see the photos from Google above and right. 

The road layout was generally 2 lanes in each direction with the nearside lane being bus lanes. There were also inset parking bays and the odd little right turn pocket. Pedestrians were confined to dashing across the traffic lanes or using the staggered 2-stage Pelican crossings placed here and there.

The new layout is striking (it's not hard!) and is seeing a cycle track created from nicking bits here and there. The bus lane is not as continuous as it was, the parking and loading is on the outside of the track (nice!), but it does appear there some loss of footway width in places which is less helpful. Clearly, TfL wasn't going to reduce traffic capacity any further.

The first three issues which I noticed were the kerbs, the drainage and the surfacing. The good news is that the kerbs are of the 45 degree splay variety which are more forgiving than normal road kerbs (although already out of date when compared to what Leicester has been doing), but the bad news is that they have been laid too high meaning there is an upstand before the splay starts which is a wheel-catcher from the start. The kerb to the left is the most important as it allows one to stay close to the footway with the one on the right less important as in many places, you are still close to traffc and would want to fall over the kerb into the traffic lane, keeping left is the key!

At this location, there is about 15mm between the surface and the
splay - wheel catching territory.
I had a chat with one of the guys on site and he told me that the upstand on the kerb is the design, so this is a TfL design issue rather than a workmanship issue. It is a logical mistake because rather than made the footway crossfall steeper, the nearside cycle track kerb is going in at the same level as the old road kerb and the track is at the old carriageway level.

The splay has a 75mm height, the old kerb would have been laid between 100mm and 125mm, so the upstand was inevitable. I don't know what the excuse is on the offside as it is a brand new kerb line. Really TfL, needs to be resurfacing and lifting the levels to give a 75mm upstand of just the splay and changing its design detail before too much more is gotten wrong.

On the subject of the surfacing, it is awful. The usual blue paint has been applied (I am totally sick of the colour now) and being a hand-laid screed, it is uneven. Further towards mile end, there is a track at footway level and seriously, it rides like some chimps have surfaced it! 

Somebody has also either messed up the level design or the gradients are so slack that there is a fair bit of puddling. There was some drizzle that morning, but water shouldn't be ponding on a new scheme like this. Lessons from Stratford haven't been learned - the first rule of civil engineering hydraulics is that liquids flow downhill!

The van is in a loading bay which blocks the view of people cycling
through the junction.
While on site, I watched the traffic for a bit as the protection ends just before the junction. In the case of Greatorex Street, there is a loading bay just before the end of the protection and what happened was drivers were starting to turn left into the cycle lane which runs through the junction. The other problem was right turns are still allowed and so drivers seem to be looking for a gap in oncoming traffic and forgetting people are cycling.

The solution here would have been to look at the side road network and allow drivers into a loop of side roads via traffic signals (which would hold those cycling) and then only allow drivers to exit from the uncontrolled side roads. The track and the footway could then been continuous to give visual priority. Alternatively, the side roads could be broken down into smaller traffic cells and some turns banned. The issue here is (and please correct me if I am wrong) that access roads are connecting to a through road and missing out a middle class of distributor road (to step up and down between the other two).

I saw some other things on my brief visit. In the photo to the right, you can see a line of "wands" which provide some separation between the traffic and those cycling (towards The City in this case). Some had been clipped and they provide far less protection than kerbs. Sadly, this is the finished job and it is about maintaining motor traffic space.

There are bus stops which have the now familiar floating or bypass arrangement where TfL has decided to squeeze the track down to single file to reduce conflict with pedestrians. There is a hump at the end of the bypass to slow those cycling to help passengers cross, but as a bus pulled in, people crossed where they wanted and so it does still sit uncomfortably. I did see some loading bays which were pretty good as trolleys could be wheeled across the track with ease.

So, the new CS2 has flaws, but it at least shows that highway capacity can be reworked to provide protected space for cycling on major roads. There is still the issue of trying to accommodate everything and everyone and that is where the compromises are creeping in. But, TfL, please, please get a grip on the kerbs and the surfacing.

* Yes, the inspiration for the title of this post is from Blackadder;

E: Great. Baldrick, what have you done?

B: I've done `C' and `D'.

E: Right, let's have it, then.

B: Right. "Big blue wobbly thing that mermaids live in."

E: What's that?

B: `Sea'.


  1. In all the consultations for this and the N/S route I religiously included reminders drawing attention to the need for splayed kerbs, so it's rather gratifying to see that TfL seems to show some awareness of the input that it gathered in the process, especially since the recently-refurbished protected lane on the eastern end of Howland Street in Camden, as with the rest of the Seven Stations Link, has the usual pedal-grabbing right angled kerbs.

    How disappointing then that the implementation here seems so half-baked.

    1. It is completely frustrating to me, because there is no extra effort or cost to get the kerb detail right. For the life of me, I can't work out why. They are also getting it wrong on the Embankment too. I am going to email them about it.

    2. Correct me if I'm wrong, but the only advantage of splayed kerbs ever mentioned by TfL is that it reduces the risk of clipping your pedals on the kerb. I have never seen them mention the fact that it reduces the risk of falling over if your wheel hits the kerb.

      That's the only explanation I can think of for why there's a small up-stand: TfL are only designing the kerbs to help avoid pedals being clipped. Avoiding wheels being clipped don't seem to be a consideration in the design.

  2. A splay kerb has a 75mm upstand on the splay which should reduce the risk of pedal strikes for most people, but the way TfL is laying them is higher (100mm to 125mm) which is more likely to catch a pedal. The vertical part of the upstand has the other effect of being more likely to catch a wheel if clipped.