The major roadworks at the Bow Roundabout are complete, indeed were completed five weeks ago apart from the opening of the contraflow beneath the flyover. Now it seems this filter lane won't be opening until later in 2025 while TfL "complete more works to protect the structure," so let's not delay my in-depth report into all the changes at my local roundabout.
The Bow Roundabout is a significant split-level interchange which opened in 1967 where the A11 and A12 meet. The former took the flyover and the latter the underpass, so it's only those switching between the two (and local traffic) who need to use the roundabout. With the opening of the Silvertown Tunnel TfL decided physical mitigation works were needed - smoothing a few curves, improving kerbs, widening a couple of carriageways and diverting the aforementioned contraflow lane. It's amazing that this somehow took five months given how little fundamentally changed, but the location of the roundabout above the River Lea brought with it additional challenges.
Traffic on the roundabout
The biggest change on the roundabout is on the Bow side where the number of lanes has been increased from two to three. I'm not sure why no other side got widened, this being barely ten-metres-worth, but a hefty tarmac stripe now eases traffic northwards. Perhaps a more important change is that there are now arrows to show traffic which lane to use whereas previously drivers were left to work it out for themselves and this often led to conflict. Everything worked smoothly if vehicles turning left stayed left and vehicles turning right stayed right, but if two drivers picked the 'wrong' lane simultaneously they'd end up manoeuvring into each other's path causing at least a honk and at worst a shunt. As a local resident I've watched this happen far too often over the last two decades. Right-turners now have two dedicated lanes so need never come into conflict, and who'd have thought the simple act of painting three arrows could have such a positive outcome?
It's still a bit early to decide if the extra lane has eased the traffic. I haven't seen any bad jams recently but I may just not have been looking at the right time. Also the Silvertown Tunnel's only been open for a week, plus that tunnel doesn't lead here anyway so goodness knows why TfL thought this roundabout needed modifying. If anything you'd expect the new toll on the Blackwall Tunnel to have reduced the traffic here all by itself.
As for traffic feeding onto the roundabout, the only significant change is for traffic arriving via Stratford High Street. Previously vehicles reached the roundabout via two lanes but now they enter via three, along a much broader front, with various longstanding hatched lines having been erased. The extra lane is to accommodate traffic arriving via the contraflow lane from Marshgate Lane which no longer has its own separate access point. Instead it diverts under the flyover, or will do when it opens, which should be a safer prospect all round. Many's the time I've forgotten the contraflow lane exists and stepped out to cross without looking both ways, so it should be harder for local pedestrians to walk in front of traffic now it's been diverted.
However this has forced the creation of an additional set of traffic lights so that two lanes from Stratford can merge with one from Marshgate Lane. It's not yet been switched on, or at least it's showing constant green, but I expect it'll add an additional delay for westbound traffic that wasn't there before. That's as well as the extra traffic lights added beforehand at the entrance to Sugar House Island and as well as the segregated cycleway which swiped a lane all the way back to Stratford twelve years ago. All these are essential but they also delay road traffic, including buses, so catching the 25 from Stratford to Bow now takes noticeably longer than it did when I first moved here.
Traffic lights on the roundabout
I got my stopwatch out before the roadworks started and have done the same afterwards, so can confirm that the traffic lights round the Bow Roundabout have been subtly rephased. What's not changed is that the entire roundabout still functions on a cycle lasting exactly 64 seconds. During those 64 seconds every approach road gets one chance to enter the roundabout, and this cycles round in an anti-clockwise direction one arm at a time.
Previously every arm got 16 seconds, regular as clockwork.
From Bow Road: 4 seconds for bikes then 12 seconds for vehicles From A12 northbound: 16 seconds From Stratford High St: 4 seconds for bikes then 12 seconds for vehicles From A12 southbound: 16 seconds
But that's now changed, with traffic emerging from Bow Road the major beneficiary.
From Bow Road: 4 seconds for bikes then 18 seconds for vehicles From A12 northbound: 18 seconds From Stratford High St: 4 seconds for bikes then 10 seconds for vehicles From A12 southbound: 18 seconds
One complete cycle still takes 64 seconds because these intervals overlap a little. But traffic coming off Bow Road now has 50% longer to enter on green which is excellent, helping to reduce queues and often meaning every vehicle waiting slips through. If the traffic backs up less often that also means fewer vehicles idling and belching fumes outside my front door so I'm all in favour. Meanwhile traffic coming off Stratford High Street now has 17% less time, which I thought was bad until I realised there are now three lanes instead of two, and that's why they've been able to reduce the time while increasing throughput.
Pedestrians
The roadworks were focused on vehicular traffic but have also had repercussions for pedestrians. Six sets of crossings remain around the roundabout, all of which have been updated to the newer style with a pedestrian countdown. But two of these crossings are now across three lanes instead of two so they both take longer to cross. One of these wider crossings is from the centre of the roundabout towards Bow and the other is across the end of Stratford High Street. I still can't get used to how much wider these are, stepping out across a tarmac chasm that didn't used to feel so vast.
And this matters because pedestrians don't always wait patiently on the pavement for the man to go green. Often they'll launch out across a gap in the traffic thinking it looks safe, whereas the Bow Roundabout is in fact a dangerous maelstrom where traffic is capable of appearing suddenly and without signalling. Make that gap 50% wider and the chance of a very nasty accident increases. Also I believe one of the countdown timings is incorrect, being a few seconds too short, so even those who've crossed properly could find themselves midway when the lights change.
Start of Bow Road: 1 lane (5m), countdown starts at 3 End of Bow Road: 2 lanes (8m), countdown starts at 5 Start of Stratford High St: 2 lanes (9m), countdown starts at 5 Stratford to centre of roundabout: 2 lanes (9m), countdown starts at 5 Bow to centre of roundabout: 3 lanes (12m), countdown starts at 5 End of Stratford High St: 3 lanes (12m), countdown starts at 8
I wonder if you can see the dodgy countdown in that list. Mostly as the number of lanes increases the length of the countdown gets longer, which is what you'd expect. One lane 3 seconds, two lanes 5 seconds, three lanes 8 seconds. But one of the 3-lane crossings only has a 5 second countdown - the crossing between Bow and the centre of the roundabout - and that's not long enough at all.
Set off on 5, as I have done several times, and you'll still be walking in front of the traffic at zero when the red man appears. I'm perfectly capable of speeding up but the elderly, disabled or child-encumbered may not be so fortunate, and the Bow Roundabout is not somewhere you want to be caught in middle of the road. If TfL's engineers are reading, that 5 really needs upping to an 8.
Cyclists
Perhaps what most surprised me about the five-month roundabout upgrade is that there've been no significant changes for the benefit of cyclists. The old blue paint in the segregated lanes is still cracking. The cycle lane at the start of Stratford High Street remains entirely unprotected. The crappy stripe occupying half the pavement on the Bromley-by-Bow segment is unchanged. It's very obvious in several places that when the rest of the roundabout got resurfaced with fresh black tarmac the cycle lanes were specifically excluded. At the end of Stratford High Street a few metres of segregation have actually been removed, this because traffic now queues further back allowing cyclists to spread out. Admittedly four cycle racks have been provided under the flyover, but no sane cyclist would leave a bike there. Things thus aren't particularly worse for cyclists but neither are they any better.
The advance cycle lights are still there, this being the first junction in London where they were introduced as a response to two fatal accidents after the blue paint first went down. A ghost bike memorial to one of those deaths is still chained to the railings above the river. So what's intriguing is how many cyclists continue to jump the lights and ride onto the roundabout anyway. The synchronisation of those lights is annoying because they're deliberately set up to stop you - if the first set isn't red the second always will be. But I did some counting for ten minutes and I reckon only half the cyclists waited and the other half made the choice to launch off past red, which is a lot more than I expected.
Many of those jumping the lights noticed no traffic was coming and launched out safely. Such times are common when the roundabout's less busy, and they were never in any danger. Others took a riskier punt, judging that they could get through a bit before or a bit after a passing vehicle and so did. But a few headstrong souls simply sailed ahead onto the roundabout without slowing down and weaved between vehicles turning left that could easily have hit them, in one case close enough that I audibly swore. There's always a spectrum of behaviour on two wheels, and reassuringly more angels than idiots, but something about the Bow Roundabout seems to encourage dangerous riding even with all the lanes and lights and everything.
All that effort to improve the junction for cars but little for pedestrians and nothing extra for cyclists - let's just say it doesn't help.
