Monday, 9 March 2015

Eliminating the risk of "Dooring": Good cycle infrastructure design keeps cyclists out of the door zone and saves lives

Alberto Paulon is the second cyclist in the image. The collision happened  few video frames after this image. Read more about the incident here and here.
A few days ago on a road in Melbourne Australia a car door was opened. Alberto Paulon was cycling past the car at the time. He collided with the door, fell into the path of a truck and, sadly, he died. This tragedy could and should have been avoided.

Injuries and deaths due to "dooring" incidents are common around the world. Such incidents are sometimes viewed as an unfortunate side-effect of cycling, a problem requiring driver and/or cyclist education. Cyclists should not be under constant threat of death depending on how they position themselves on roads. There is no reason for roads to be designed in such a way that danger results from mistakes by their users when they could be designed to reduce the chance of mistakes becoming tragedies.

Door zone collisions can be almost entirely eliminated by changing the design of roads. This blog post illustrates how that can be done.

What's wrong with Sydney Road, Melbourne ?
The road on which this incident happened is in the Brunswick area of Melbourne, which has a high rate of cycling for an Australian city. Unfortunately, while the people who live in and use the shops in this area cycle quite frequently, the road is designed to serve those who are passing through in motor vehicles and no proper separate space has been found to keep cyclists safe.

A twenty-one metre wide road is more than wide enough to allow cycling in safety, and more than wide enough to provide cycling facilities which are free from the "door zone" problem. However this will require making a choice of what the purpose is of Sydney Road.

Is the purpose of Sydney Road to provide a route for trams, for motor cars and trucks or is it a local shopping street. While there is an attempt to make this road serve all types of users it is likely that it will not serve any of them well. Cyclists are amongst the most vulnerable users of any road and therefore amongst those users most likely to be injured or killed as a result of inadequate infrastructure.

A narrower road in Assen is much safer for cycling
The photos below come from Groningerstraat in Assen. Groningerstraat is a through road of approximately 18 metres wide. This makes it three metres narrower than Sydney Road in Melbourne. Despite its relative narrowness, Groningerstraat provides a very high quality environment in which to cycle. It's very convenient and also very safe. Dooring is almost impossible in Groningerstraat.

Layout of Groningerstraat. 18 m in total are divided between 1.8 m wide pedestrian paths, 2.2 m wide unidirectional cycle-paths, 2.8 m wide lanes for motor vehicles leaving space for green buffers, drainage and car parking. Thanks to Streetmix.
Safe, sociable side-by-side cycling is possible in both directions along Groningerstraat.
Car parking alternates from one side to the other along the length of the road. The pedestrian and cycling infrastructure is constant.

Angled "forgiving" kerbs are used so that a cyclist who makes a mistake and collides with the kerb will simply mount the pavement and continue for a while rather than being injured. Note that in this photo the cyclists shown are riding racing bicycles. It was taken during one of several large racing events which take place in Assen. Racing cyclists use cycle-paths in the Netherlands because there is no advantage to riding on the roads.
The drain provides a gap between parked cars and the cycle-path. It provides a significant part of the total space required to open a car door. In any case, the cycle-path is wide enough that two people can pass an open door side-by-side in safety. If there are more than two side-by-side then cyclists can mount the forgiving kerb should they have to. Remember that in the Netherlands it is usual to ride on the right so most people wouldn't come close to a car door and in any case there is no risk of falling in front of a motor vehicle if they crash for any reason.
There are several reasons why cycle-paths in this position do not create a dooring risk.
  1. It is normal in the Netherlands to cycle on the right, and that places an individual cyclist as far away as possible from parked cars as they are passed.
    1. The drain / buffer between parked cars and the cycle-path is wide enough for a significant proportion of the total car door side.
    2. The cycle-paths are of a width which allows two cyclists passing side-by-side to very easily pass an open door in safety.
    3. If a cyclist swerves away from the car then they may meet the kerb between the cycle-path and the pavement, but this is an angled "forgiving" kerb over which it is possible to cycle in safety so swerving won't result in injury.
    4. The Netherlands is a left hand drive country. Therefore doors of cars parked in the conventional direction (the blue car above is parked against the flow) will most frequently be opened on the opposite side of the car from the cycle-path.
    5. This is residential parking, not business parking. Therefore car movements are less frequent and car doors opened less often.
    6. It is possible for cyclists to swerve, stop or even crash without any danger of being run into by a motor vehicle. This means that the very worst outcomes are avoided because riding straight into a car door won't result in a secondary collision involving another motor vehicle - the cause of the death in Melbourne.
    Subjective safety principles require designing roads so that they are easy to use and forgiving of mistakes. These principles are credited with reducing the rate of injury and death on Dutch roads.

    Other Dutch examples
    A through road in Groningen with shops on both sides. Layout is similar to Groningerstraat, but this older example doesn't have a forgiving kerb or a gap between parked cars and the cycle-path. In-between parked cars there is additional danger to cyclists due to the metal posts shown above. Such posts should never be used to separate cycle-paths from roads. On colliding with such a post, a cyclist will almost certainly fall and that fall could be onto the road where a secondary collision with a motor vehicle is likely.
    A less good example from Assen. Because the cycle-lane is on the wrong side of parked cars, there is a risk of dooring resulting in a secondary collision. On-road cycle-lanes are not good cycling infrastructure. In this case there are factors which reduce the risk. A 0.5 m buffer between parked cars and the cycle-lane offers some space for a door to open and the 2 metre width of the cycle-lane offers some swerving space for cyclists. Also these cars are parked by residences so do not move so frequently as they would if parked by shops. Note that at this location also the motor vehicle lanes are 2.8 m wide. This is wide enough for all vehicles.

    This road leads through villages south of Assen, providing a safe route for cyclists to the city and beyond. Approximately 1 km of the route is shown in the video. On the other side of this road there is a canal. It would make no sense at all for cyclists to have to cross the road in order to ride in the opposite direction to that which I'm riding in so a bidirectional cycle-path is provided on one side only. This is older infrastructure so not ideal in several ways (narrow for a bidirectional path, not always a smooth surface) but it functions well and provides another example of how to deal with on-road parking and entrances.

    Cyclist injuries are rising across the English speaking world

    Tracey Gaudry from the Amy Gillett Foundation is quoted in the ABC news story as saying that The road toll is decreasing across the country on the whole except for bicycle riders. So what is happening is that the work that is being done to protect occupants of motor vehicles, not enough is being done to protect vulnerable road users, including bike riders." The same is true across most English speaking countries because while there has been a rise in the numbers of people cycling, there has not been any significant improvement in the safety for cyclists.

    The blue line shows a clear rise
    in cyclist injuries in the UK.
    I have long been of the opinion that the concept of "safety in numbers" is a myth. Recent increases in injuries where the cycling infrastructure has not been improved would appear to confirm this (for example, recent statistics from the UK). The Netherlands has the best cyclist safety record in the world because the infrastructure is designed in a way which reduces the chance of cyclists being involved in collisions which could result in injury or death. Countries which do not follow this lead

    Click here for details of the study tours.
    Lots of "Sydney Roads", not many "Groningerstraats"
    Many roads across the world have the same problem as does Sydney Road in Melbourne. Many of them could be improved by following the same engineering principles as are demonstrated above. On the other hand, there are relatively few roads like Groningerstraat in which these principles can be demonstrated. That is why this road has featured on our study tours since it was rebuilt in 2007.

    Groningerstraat also demonstrates other examples of good design, such as an extremely safe and convenient traffic light junction and a very well designed and safe side-road crossing. Assen has many examples of good infrastructure which extend well past this one road. To see and learn from these and other examples of good design as well as to have problems caused by bad designs pointed out, book a study tour.

    There is a campaign in Melbourne which has been calling for a cycle-path along Sydney Road for some time.


    Tom said...

    I recently moved to San Francisco that signed up for Vision Zero
    I think Melbourne should do similar. It changes the whole thought process, accepting that people make mistakes, but that those mistakes shouldn't be fatal.

    I feel like a push to signing up to such an initiative should make the need for protected bike lanes on roads like Sydney road more obvious once the goal is set and the engineering process is reset to start with the position of people making mistakes.

    marven said...

    Also part of the conversation is traffic volume and speeds. Most Dutch riders willingly put themselves in the door zone on streets with no infrastructure whatsoever, but those streets are generally not filled with fast-moving traffic, especially with (m)any trucks. While I recognize them as not best practice, I don't mind them per se if the parking turnover is low as are the speed and volume of motor traffic on the road that they're on.

    Khal said...

    Some very good points here. One, that form follows philosophy and if one signs on to Vision Zero, one will avoid designs that have high probabilities or high consequences of failure. Two, the author questions the uncritical acceptance of "safety in numbers". That is good because safety doesn't just happen. It reflects a variety of interactions such as better infrastructure, slower speed limits, and attention to detail. Third, the author mentions that on road facilities are a bad idea. I think one has to look at a situation first and then decide what is the best design. Low speed limits coupled with good visibility may argue for an onroad design vs a poor visibility segregated design. The devils are in the details. Nice article.

    Rebecca Albrecht said...

    Even though I ride five feet from parked cars to avoid the door zone, cyclists riding behind me in a bike lane, will see that empty space I am not riding in, and pass me on my right, beside the parked cars. I am fearful that an opening car door will knock them over or the cyclist will swerve into me knocking me into the path of an oncoming car.

    I was told that there is no dutch word for "to be doored" I rode with my dutch cousins in Amsterdam and they rode right next to parked cars (on a quiet street). I think they were safe from being doored because people learn from a very young age not to open a car door without looking. Once when I was in a car with my dutch aunt in a small Dutch town, she warned me to look for cyclists before I opened the car door. It is second nature to a dutch person to do that. Even now though I know better,I will still occasionally open a car door here in the US without looking.

    Alex S said...

    As a regular cyclist and resident of Melbourne, I avoid roads like Sydney Rd because they are too dangerous. The tragedy is that a coronial inquest recommended more separated cycling infrastructure about 3 years ago, but very little has been built. This inquest examined an almost identical death of another young cyclist on a similar road. However, the removal of on-road car parks in this place is almost treated as heresy. If only our “leaders” would look at the evidence from The Netherlands!

    arcady said...

    Getting doored is terrible, and I've had it happen a few times. Fortunately, in those cases, there were no cars coming up from behind (indeed, I have to wonder how often cars get "doored"). One other related danger is cars pulling out of parking spaces without looking, and especially cars making a U-turn straight from the parking lane. Riding on a street with parked cars, you have to watch out for cars behind you, doors of parked cars, parked cars pulling out, cars pulling out of driveways, cars in the opposite direction turning left, and even cars in the opposite direction abruptly deciding to "flip a bitch" (make a U-turn) right into you. Having a separate cyclepath reduces the potential conflicts, and thus the stress, to a much more manageable level.

    Adrian Lobo said...

    Thanks again David for illustrating with real examples how sustainable safety design and infrastructure investment should operate to protect vulnerable road users. Australia's issue is that urban sprawl has made too many voters car-dependent and thus insistent on prioritising motorist commute times and convenience. Tractable pathways at various levels (urban and land use policy, job distribution, sustainable safety, infrastructure changes) toward an enlightened vision of access and mobility are necessary.

    You can read more details about the Melbourne/Australian context for these issues here:

    opusthepoet said...

    The annoying thing to this is you can see the remnants of a bike lane under the parked cars in the CCTV footage. The bike infrastructure is there already, they just need to move the parked cars off of it.

    NIKDOW said...

    Don't we wish Sydney Rd could be this good? One thing David doesn't know is that Sydney Rd has trams. I think that means parking has to go altogether. BTW trams are part of the reason Sydney Rd is a popular shopping strip with lots of pedestrians, shops, cafés restaurants etc. Personally I never use the tram as the bike is quicker & more flexible at either end of the journey but they are very popular & much loved here.