When the Silvertown Tunnel opens next week, one thing the Mayor will enthuse about is the new Superloop bus route running through it. People like the Superloop, they know it gets them places fast, so no doubt they'll be enthused too. But the new SL4 isn't going to be as super as people might think, nor as fast, because in this case SL might as well stand for Stopping Lots.
There are two kinds of Superloop route. The SL1/2/3/5/7/8/9/10 are limited stop services, pausing only at key points to pick up passengers who want to travel longer distances. Then there's the SL6, the former X68, which should never have come under the Superloop umbrella in the first place. It stops at every stop except for a five mile hyperleap in the middle, all the better for whisking commuters rapidly between West Norwood and Waterloo. It also only runs during the rush hour and then only in one direction, which is why barely a thousand passengers use it daily. But the important thing is that it stops lots at one end, lots at the other end and not in the middle, which is precisely what the SL4 is about to do.
The SL4 starts at Westferry Circus, which is near enough but not quite Canary Wharf. Were this the normal Superloop it'd only stop outside the station, maybe once more to the east, but instead it'll stop eight times on the way to the tunnel. Every stop between Canary Wharf and the tunnel portal gets an SL4 tile, every single one. Then comes the big dive under the Thames, deliberately not stopping at North Greenwich because that would slow things down. And after climbing to the fringes of Blackheath it then stops at every single stop all the way to Grove Park, every single one. Nine stops, three mile gap, seventeen stops. Hardly Super.
When the route was announced everyone wondered why the SL4 wasn't continuing to Bromley because a fast bus between Canary Wharf and Bromley might have purpose. But it was never intended this would be a fast bus, hence the SL4 merely serves the Lewisham/Greenwich fringes and then grinds to a halt. Should you ever need a bus between Blackheath and Grove Park it'll be great because you'll be able to do it in one bus rather than switching between the 202 and 261 in Lee, plus a bus will come along more often. But the only Super bit of the SL4 is the non-stop section mid-journey, and arguably that isn't especially super either. It starts here.
This is the last stop before the Silvertown tunnel heading north. It's at the Sun-in-the-Sands roundabout where Shooters Hill Road meets the A2 dual carriageway, two whole miles from the tunnel portal. It's not near any stations, nor an especially easy place to get to, nor somewhere you can reach North Greenwich quickly from. And yet this is the last place south of the river you can board or alight, the stopping pattern assuming that what you really want to do from here is go to Canary Wharf, not anywhere inbetween.
If the Silvertown Tunnel had been built with public transport in mind, someone would have included a bus stop on the approach to the tunnel portal which passengers on the peninsula could use. When they built the Blackwall Tunnel they added just such a layby for the 108, and admittedly it's an unpleasant place to wait but it's better than not being able to catch the bus at all. Alas the Silvertown Tunnel has no such provision on either side so buses can only whizz through without stopping.
It's just as non-stop on the northern side. The SL4 emerges by a snazzy new gyratory but there's nowhere to stop so it doesn't. City Hall is close by, also the Royal Docks, the Dangleway, Royal Victoria DLR and lots of flats, but no way to get on or off. Indeed although the SL4 emerges in Newham it doesn't stop anywhere in the borough so there's no easy way to make onward connections. Serving Newham is the 129's job, the other new bus through the Silvertown Tunnel, but at no point do the SL4 and 129 stop anywhere near each other so potential interchange doesn't work either.
Instead the SL4 launches across Bow Creek via the Lower Lea Crossing, landing after half a mile at the Leamouth Roundabout. No other London bus does this so there's never been a bus stop up here and they haven't added one. We're now in Tower Hamlets on the Leamouth Peninsula and it's time for the SL4 to make its first stop north of the Thames. Almost inexplicably it does this by bearing off the roundabout, doubling back down the ramp and stopping underneath the flyover. Ridiculously for a so-called express service that first stop is here.
This is Orchard Place, a backwater road which ten years ago you'd only have visited if you were hiking to the cultural outpost of Trinity Buoy Wharf. It first gained a bus service in 2017 when hundreds of new flats started to be built at City Island, joined since by hundreds more at Goodluck Hope. Route D3 already terminates here four times an hour and is about to be joined by the SL4, in both directions, running twice as often. That's brilliant if you live here and want go to Canary Wharf, but less useful if you thought you were riding a fast bus and find yourself dawdling down here instead.
There is a reason for this detour which is that the public specifically requested it. In their 2022 consultation TfL asked whether respondents would prefer the new bus to take the most direct route or to go via Orchard Place to serve the Leamouth Peninsula. "Our preferred option is the direct route", TfL wrote. But the public disagreed, quite significantly...
... hence the extra twiddle. My hunch is that the London City Island and Goodluck Hope Leaseholders’ and Residents’ Association strongly encouraged their leaseholders and residents to respond to the consultation, and this pile-on swung the results decisively in favour of Orchard Place. The LCIGHLRA didn't get everything their way. In their submission they also asked for a 'vital' extra stop at North Greenwich for the benefit of their residents, and also could the bus please go to Lewisham because Grove Park lacked useful amenities. But they did get TfL to gift them 250 extra Superloops per day, so you can curse them for the delay should you ever decide to take a ride.
The SL4 was originally supposed to approach its destination through Wood Wharf, Docklands' new eastern upthrust, rather than entering direct. Fortunately the roads through Wood Wharf aren't ready yet and won't be until 2027 so the quicker route wins for now. But it's still not going to be especially quick. Grove Park to Canary Wharf is timetabled to take an hour in the morning peak, 45 minutes during the day and, OK, just 35 minutes on the last bus after midnight. Even the express section in the middle could take anything from 13 to 20 minutes depending on the traffic. And all this will be running remarkably often - every eight minutes from 6am to 8pm - based on the untested proposition that thousands of people want to travel by bus to Canary Wharf from a thin sliver of southeast London.
I should say that back in November 2022 when TfL first proposed the SL4, then called the X239, they provided an extraordinary amount of detail on why they chose this particular route. I summarised what they said in this post here, and basically it's because their planning models suggested this was the best way of maximising demand. If you want to mouth off and say "But I don't see why they didn't..." go read that first.
My hunch is that the SL4 will be an insanely frequent white elephant of limited use, made worse by the lengthy gap in the middle. But it'll also be free to use for the first year which'll bump up its ridership no end, especially for local journeys in Lewisham where only a fool would board a 202 or 261 when they could board the SL4 for free. It will thus appear hugely successful, its ridership figures inherently meaningless, and the Mayor will clap his hands and say I told you it'd be brilliant. As with so many dubious projects it'll only look great to those who've never ridden it, the frankly baffling SL4, Stopping Lots.
