Cycle Gates - A Useful Tool

There are lots of tools out there which we can use to make cycling safer and while I can understand that people would love to transform their towns overnight, I'm afraid that we will often have to go for incremental improvements, especially if we are starting from a low base.

There many are urban main roads in the UK which have left us with a legacy of motor traffic movement being prioritised. At best, pedestrians have green men crossings to negotiate the junctions but cycling has never been considered unless bolted on to pedestrian space or people left to mix with traffic. These roads have junctions running at capacity (sometimes over capacity) and so the slightest change will cause an increase in congestion which is often a politically unacceptable position.

The challenge here is how can we add protected cycling infrastructure without immediately destroying junction capacity while not giving up on the protection in the junction. We could take the purist approach and say "tough" and just put in a brilliant new layout for walking and cycling, but in the real world where there is politics at play we just might have to do something now and come back with that great scheme once we have an actual functioning cycling network.

That was a long-winded bit of scene setting for a look at what I think is an underused tool which we can use for that initial/ interim period, and that's the cycle gate. It's a subject I did look at for dealing with pinch points at bridges before, but which needs a more general airing. 

Above is an example of a cycle gate at Bow, London, which relies on separated cycling and driving space ending at traffic signals which separately control each flow and a stop line further ahead with its own separate signals (often called the reservoir signal). Cycles get a green at the first stop line while traffic is held at its first stop line. Then the far stop line gets a green a few seconds before the first traffic stop line which allows cycles to clear the junction before drivers catch up. I also found a couple of examples down in Lambeth when I went for a mooch about last year.

The problem with the arrangement is when the traffic gets released from the first stop line (and then passes the second which has already a green signal), cycles are stopped at their first stop line which means the arrangement is going to be an "always stop" for cycles whereas in theory, general traffic can encounter a "double green" to pass through.

It's also worth remembering that traffic signals are traffic management rather than safety devices. Cycle gates are going to be safer than cycle tracks just giving up at junctions (on a like for like basis) with the risk of left hooks and difficulty in turning right addressed, but they are clearly not fully separated cycling infrastructure. They also suffer from the usual rules-based problem of they only work properly when everyone follows the rules.

At least from the bit of research I have done and from what my fellow geeks have said on Twitter (thanks Alex Ingram), it seems that cycle gates are a more modern idea, but have their roots in the mid 1980's/ early 1990's when Advanced Stop Lines (ASLs) were being trialed. Barnby Gate in Newark is particularly interesting because it used to have separated traffic signals at an advanced stop line (above, from Traffic Advisory Leaflet 8/93). The blue sign in the photograph says "CYCLES when red light shows wait HERE. 

When you have a look on Google Streetview of the junction, this layout has gone, but there's a tantalising nugget of another sign which says "MOTOR VEHICLES when red light shows wait HERE". The sign was there in 2020, but now appears removed. 

When viewed against the original layout, this very much appears to show that the two stop lines were under separate control and the fact the first signal is showing a green cycle symbol means that cycle traffic could advance to the second stop line and it also means that second stop line could run green before the first which would have allowed cycles to be released before general traffic and be through the junction.

It's not quite a cycle gate as we know them now, because from the first sign and the use of the green cycle symbol at the first stop line, cycles were never stopped at the first signal. It is therefore more likely that this was actually an early release style arrangement which eventually ended up a standard advanced stop line which are less favoured amongst those designing high class cycling infrastructure today.

Whenever I have a dig into the archives it always seems so sad that we were starting to try different things back in those days. Imagine if we had actually developed these ideas to become commonplace. We've lost a generation to carrying on down the motor-traffic first route, but let's wind it forward again to my first photograph which is of the Bow Interchange in East London.

Prior to the cycle gate being installed (2008 above), there was no protection for cycling and the environment was hostile to walking and wheeling too. Then came Mayor Johnson who decided that painting blue stripes on busy roads would create the conditions where people would want to cycle. 

On the other side of the junction, a large ASL was painted in along with a nearside blue stripe which crossed a slip road and accessed an island separated cycle track (above). The approach to the ASL also had a blue strip, but no actual cycle lane. On this side of the junction, Brian Dorling was left hooked by a truck driver and killed which led to a rapid rethink and roll-out of cycle gates on both sides of the junction because the layout contributed to Dorling's death.

The cycle gate design was incorporated into the London Cycling Design Standards in Chapter 5 and it started to appear across the Capital and now it features in devolved national guidance and can be considered as a standard treatment. Above is a schematic from Scotland's Cycling by Design guidance.

Transport for London commissioned TRL to undertake a review of cycle gates and the outcome was published in 2018. Two sites were reviewed to see whether and how cyclists used the cycle gate, including compliance with signals at different stages and to see if general traffic was able to clear the reservoir (the area behind the second stop line). The locations were on Lambeth Road and Queen Street Place. 

The first doesn't take users into protected space, although the ahead movement joins a quiet street which is part of Cycleway 6 and the approach to the cycle gate has no protection. The second leads from the well protected cycle track on Southwark Bridge (actually parapet protection done cleverly) via a short section of mandatory cycle lane. It then allows users to turn left or right onto Cycleway 3 or continue ahead into a quiet street and so is essentially a fairly protected junction for cycling.

Given the two different contexts, the unsurprising result was on Lambeth Road, 38.5% of cyclists used the general traffic lane, whereas on Queen Street Place, just 3% did. This is because with the latter, it forms part of a local network whereas the former is a point treatment and so some people are choosing to grab a general traffic green rather than face the "always stop" nature of cycle gates and that's worth remembering when we deploy them. And of course, yes, there were some cyclists ignoring red signals because this is what happens with motor traffic management when applied to human scale movement. The study is mentioned in passing in TfL's round up of cycling innovations in 2018.

So, back to the use of the technique as an interim tool. We have a fully formed urban motoring network and as I mentioned above we don't often have spare capacity to play with at the junctions unless there is a strong political decision to move it to other modes. It is hard to retrofit a cycling network to such a system because in order to give as many people the option to cycle as we can, we need a good cycling network. Unless an area gets a huge and sustained investment over time, it's not going to happen quickly and so there's the chicken and egg of building stuff that won't be busy to start with because it doesn't form a network.

It is fairly easy to drop in some light protection to give space for cycling on the links (the sections of road between main junctions), even if that loses traffic space or lanes because it's usually the main junctions which create the capacity constraints anyway. Signalised junctions which have been in place for many years will often have utilities woven around them which means a complete rebuild for cycling will be carrying a legacy of utilities which can really add to the costs. We should also remember that so much of the stuff on our roads and streets is motoring infrastructure anyway.

The good thing about cycle gates is they can usually be fitted in before a lane flares to two or more at the junction, although the immediate disadvantage is lane and destination markings are not permitted in the reservoir. The sketch above is one main road approach to a T-junction roughly based on a junction I cycle through a fair bit. the sketch below is the same basic layout but with a cycle gate added.

The footways are untouched and so all changes made within the existing carriageway with utilities unlikely being impacted. There will be new and adjusted traffic signals, but this is about as low cost as we can get and so should be a very attractive way to deal with signalised junctions as we build networks.

There will be a capacity impact though. Drivers won't be able to get side by side at the first stop line as they can with the untreated junction and so it means the length used for side by side queuing of about 5 car lengths in my example will add to the queue length if usually filled. On the flip side, once drivers get a green they can turn left slightly more quickly as they would be moving by the second stop line. The two won't balance out completely and so additional green time might be needed which itself impacts capacity elsewhere. From a pedestrian point of view, crossings simply run as they did before.

There is a penalty to motor traffic capacity, but it is far smaller than compared with a fully protected junction and it is far cheaper to deliver. For an emerging network, some light protection and cycle gates could help roll something out more quickly and allow adjustments to be made as cycle volumes grow enough to "justify" (in mainly political terms) of a more radical intervention. 

So far, I haven't seen or heard any cycle gates being used outside of London and I'd be interested to hear of any that pop up. There are quite a few which have similarities with the Newark example such as the interesting layout spotted by Revchips in Gateshead (above). There are two distinct stopping points, but the first signal doesn't totally separate out cycles and other traffic so that a cyclist arriving on a green is mixing with traffic going into the tunnel, although when red, there is a steady cycle signal showing green to get cycles ahead. There is loads of space here to convert this to a cycle gate if needed.

It's interesting to see the hints of innovation from decades ago, although as is often the case, things didn't really develop. It is good to have another tool in the box, especially one which can be added fairly easily and means rolling out a network far more quickly and cheaply than having to reconstruct everything.