Will you let your 10 years old kid to cycle one 1 km to school? …. Why not?
Most parents will tell you that although the bicycle path is safe, they worry their children may be killed when crossing the roads.
What if there is a bicycle path, off the road, connecting home and school?
“That will be much better.” a friend once told me. “Free from the danger of cars, I will seriously consider to let my son to cycle to school. After all cycling is a healthy way to move around, providing much needed physical exercise in today’s computer age. I think it will also helps him to become more independent and I won’t be so stressed during the morning rush hours.”
However, it is not realistic to assume the bicycle network can always be kept “off the road”. As the network grows into towns, it is inevitable that the bicycle network will have to intersect with the road system at some intersections. If the road crossings are not safe, the cycling path is broken at each road crossing. The entire network becomes a bunch of isolated off-road paths.
Therefore the objective of road crossing design along a bicycle path is to make it easy and safe to cross the road, to connect and reassure parents that it is safe for their kids to cycle across the road independently.
Cycling as a lifestyle choice will be a major step for Singapore to move towards a more green, clean and livable city. URA, together with key government agents such as LTA and NPark, are extending current 230 km of bicycle network (mostly Park Connectors) to more than 700 km by 2030. We can be duplicating existing (safety) problems if the new (off-road) cycling path is built with existing intersection design. Therefore now is a good time to consider how to improve the safety for all road users at intersections and road crossing.
Why existing traffic intersection is not safe enough?
Let’s take a fresh look at traffic intersection today. The diagram (2) below illustrate a typical intersection design, based on a traffic junction at Tampines Street 44-45 and Avenue 9. As a cyclist, or pedestrian, if you need to cross Street 44 from bottom to top, you will encounter 2 high risk “conflicting points” where fast moving cars may be coming from your behind.
The first “conflicting point” is right at the beginning of your journey, left turning car from Avenue 9 may run over you from behind (right). To be aware of the danger and prepare to take evasion action you have to check behind while moving forward onto the road. This is not natural, and very difficult to do while on a bicycle. If the turning vehicle is a large lorry, you likely to be at their blind spot. You can be rear wheeled without the driver even notice.
The second “conflicting point” is the entire stretch before the centre road divider, the driver at the diagonal side of the intersection is watching carefully at the on coming cars (not at you!), waiting for a window of opportunity to make a right turn. The pedestrian crossing is the first location that is not on the path of coming cars. That driver are likely to dash into your path for their own safety, they need to escape the flow of on coming traffic. Under such stressful condition, some drivers forget to check cyclists and pedestrians before they make the quick turn. If you are crossing Street 44 from top to bottom, the situation is even worst, because this car is now turning into you from behind, making it impossible for you to check and be prepare.
The entire crossing is 18 meters. There are two high-risk conflicting points. It can take between upto 60 seconds, depends on age and mobility.
Alternative intersection design (Dutch)
Luckily we don’t have to re-invent the wheel from scratch, problem we face today is not new, we can learn from the Dutch who are more advanced in integrating bicycle as a key transport modes. Over the last 40 years, the Dutch has developed, and systematically refined their traffic intersection design such that it is not only safe for cyclists and pedestrian to use, it is also safer and more efficient for motorists too. With the help of my friend Maurits (who gave a presentation of Dutch bike infrastructure to LoveCyclingSG members and at URA in Februray, 2014) I managed to obtain the design template of a typical Dutch solution to traffic intersection – a special roundabout design that eliminate the dangerous “conflicting points”. I will start with the “ideal solution” in this post, and later follow up with some “in-between” solutions possible.
The ideal solution: Dutch roundabout
The diagram (3) below make use of the same space as in diagram (2) and following the dimension based in the Dutch design specification. No additional space is needed.
Let take a look at how this roundabout work in real world (Video):
First thing you’ll notice is the entire crossing distance is shorten to 1/3 of the original, 6.5 meters instead of 18 meters. That means cyclists and pedestrians will be able to clear the crossing in 1/3 of the time. This assure motorist and make them more likely to wait because they don’t need to wait for long. More importantly, previous first two dangerous “conflicting points” are eliminated. It is now easy for both motorist and non-motorist to watch out for each other because they are facing each other. Thirdly, right turning drivers (at the diagonal opposite site of the intersection) now have a safe space to pause and wait, they are not stressed to dash onto the pedestrian crossing for their own safety.
There is no need for cyclist to “dismount and push” as such crossing. Clear line of sight between motorists and other road users give both parties enough time to react to sudden, unexpected events.
Compares to current intersections in Singapore, this design is a lot safer and more intuitive, there is no need to use traffic signal lights to regulate the flow. This special roundabout is a “continuous traffic flow processor” that produce the optimal balance of car and human flow. Some people may think that the (car) traffic capacity is reduced because more cars are able to clear the current intersection during the the GREEN light phase. But they forget that they have to wait for the RED light phase and sometime it is waiting for nothing. Some others may doubt if Singapore drivers are able to handle such special design. Fortunately Singapore drivers are already responding positively to similar roundabout. If you drive to NTU, there is a small roundabout (missing the facilities for cycling) near the ADM Building. I was told that there use to be a lot of accident at that intersection because it is on a slope. After changing to this roundabout design the accidents rate has been reduced significantly.
Facts sheet: Dutch roundabout
In the Netherlands: over the last 30 years, traffic intersection has been systematically replaced by roundabout. By 2010, there were 3900 roundabout in the Netherlands.
Capacity: 25,000 cars/day. Waiting time is usually shorten for motorists.
Casualties: reduced by 70% (light and serious injuries)
CO2: reduced by 21%
This special Dutch roundabout design may not be applicable to all road intersection, yet the design thinking behind can always apply to any crossing:
1) Prepare motorist before they reach the pedestrian/bicycle crossing. (optimal approaching speed = 30km/hr)
2) Give time and safe space for drivers to response to cyclists and pedestrians
2) Make it easy and obvious for cyclist and pedestrian to notice where the car is approaching (“fail safe” approach)
Although the example is in Tampines, but this idea can be prototyped and tested easily in any existing location with similar space.
I will be sharing this Dutch style roundabout design with LTA and relevant agents. feel free to post your comments here so that I can take your view into consideration when talking to the government agents.
2014-04-09 Chu Wa, Francis
Update: 2014-04-29 more information about roundabouts
(USA) Myth Buster comparing 4-legs intersection VS roundabout. Roundabout is 20% more efficient than a 4 legs intersection.
(USA) Roundabout causes more accidents? (This is an example of poorly designed roundabout, with too many signs distracting the drivers)
(USA) Roundabout is safer and more efficient (this is not yet the best design, car entering the roundabout tangentially make it unnatural to reduce speed)