Some people notice things in my videos that even I don’t, or they ask questions about stuff I had never really given much thought before. The Dutch drainage system is one such topic. Paul James noticed the drains in one of my videos, which prompted Mark Treasure from As Easy As Riding A Bike to write a blog post about them. Emmanuel Marcel Favre Nicolin from Brazil also mentioned how well the Dutch cycle paths are usually drained. Someone else then asked if I could perhaps write a blog post about the Dutch drainage system and well… here it is!
At first I thought I wouldn’t be able to say much about this. After all rain is not unique to the Netherlands and neither is infrastructure. To keep infra usable under wet conditions you need a system to drain your streets and that is true for the entire world. What could be the big deal about the Dutch way to do it? But with the remarks of Mark and Emmanuel in the back of my head, I started to search the internet.
If you are used to hazardous grates directly in your path as a cyclist like many people also in the UK are, then it is a big deal to think about these things. Examples on the internet show that a lot can go wrong as well without good drainage. Such as this video of a flooded Sydney cycle path.
With so many people cycling in the Netherlands and with the average amount of precipitation in their country, the Dutch need a system that keeps the infrastructure dry without endangering all those people cycling. And of course the Dutch have such a system. Key difference to some of the other systems of the world is that the openings for rain water to get into the sewer system are not horizontally in the street surface, but vertically set in the kerbs (curbs of you are not from the UK). As a cyclist you do not have to ride over these openings that way and that makes all the difference. The system is fairly similar all over the Netherlands (and a lot of other countries in Europe) and it has been in use for quite some time. I don’t think the system was invented by the Dutch though. The Dutch drains look too much like the drains of the Paris system that is even older. The only difference to the Paris system is that the Dutch don’t use extra water to flush the gutters. It rains so often in the Netherlands that flushing happens all by itself!
After a study tour of the Netherlands some students of the Northeastern University of Boston explained the system:
Drainage
Many of the Netherlands cycle tracks are at sidewalk level or an intermediate level. They are pitched down toward the roadway, just like typical sidewalks. Drainage is then handled by roadway catch basins.
Street level cycle tracks separated by a median have their own small catch basins, spaced out along the cycle track to capture runoff from the cycle track and from the sidewalk that is pitched toward it.
Engineers usually place drainage along cycle tracks that have a high curb, just like they would for a normal road. The catch basin grates are usually smaller due to the smaller impermeable areas. When cycle tracks have no curbs or are pitched on sidewalk or intermediate levels then water will flow into the road where the engineers will have taken this impermeable space into account and have appropriately sized catch basins.
Well, there you have it. I couldn’t have said it any other way. It is plain and simple and it works well. But it underlines once again that what makes riding a bicycle pleasant is in the smallest details! You have to get every detail right to get the experience right as well.
To make this post complete, here’s the complimentary video!
Video explaining the drainage system in the Netherlands.
BICYCLE DUTCH 
I used to ride a motorbike. Any motor like training goes on and on about hazards from inspection chambers drains etc in the road surface. They are hazards. Design them out. Full stop.!
USA is not the good example for infrastructure. There is so much to do that it looks as if the easier way would be to rip it all up and start from the scratch. This is just painting over mistakes, making it LOOK-ALIKE but not WORK-ALIKE. Same with cars, subways, trains..telephones, banks..you name it.
Here in Brazil. The problem is much deeper! Drainage is often non existent! But we do have a good engineer here in Vitória. The last cycle path was delivered with a drainage kerb sistem that should work and looks externally pretty similar to the dutch one! Theoritically, that should be ok but I’ve been told that the drainage of the cycle was not really connected and drainage is not working.
In fact drainage in Brasil is very deficient in streets and cycle path! Good to know at list that theoritically our engineer is good here. We are though sttil missing one part with importante things like conecting drainage… Not so easy here!!
Chicago doesn’t have curb drains, but many suburbs do.
The drain grate you posted from Chicago isn’t dangerous except when this happens:
1. The grate is clogged and flood forms.
2. The grate is clogged in the winter and an ice patch forms.
3. The asphalt around the grate changes grade/elevation and forms a bump.
Even when that style of grate is wet (from a rain), it’s not very slipper. I don’t want to defend this grate, but “it’s not that bad”.
Hat dies auf nürnberg2rad rebloggt und kommentierte:
So könnte Ihr Fahrbahnrand aussehen. Schön flach ohne versenkte Kanalgitter!
Dankjewel Mark,
another well-investigated post on a topic, which is very important but not specificly obvious in everyday use. Here in Germany most grates are horizontally placed and reduce about 40cm of the right side of the road. There where you are suposed to ride. Very annoying in narrow passages, especially when these grates fall a few cm below road level after some years.
Thank you!
Excellent post, as always. Equally bad in my opinion as poorly positioned drains are the ridged tactile paving slabs that are all too common in the UK (sorry I don’t know the proper name for them but see http://www.rudi.net/node/21479 for an image).
They are often used to separate the pedestrian and cycle parts of shared use paths. The ridges are turned 90 degrees across the path for the pedestrian part.
These can be lethal in the wet. The ridges collect little bits of slimy, mossy matter that is VERY slippery when mixed with a bit of rain. They are often positioned just where you are turning and/or leaning over and trying to negotiate a junction at the same time.
Yet another example of a complete lack of understanding of how people actually ride bikes.
Are these used anywhere in the Netherlands?
They are called Corduroy Hazard Warning Surface. see Chapter 2 of https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/3622/tactile-pavement.pdf
As always Highway Engineers have to work to specified guidance, and it isn’t a case of a lack of understanding but a compromise to accommodate the visually impaired.
Paul, thanks for the explanation. I’m sure they are installed with the best of intentions but for cyclists they are just another danger you need to keep your eye out for.
My question should perhaps be: how do the Dutch cater for visually imparted people on cycle paths?
The dutch system has a disadvantage. It’s not just the rain that keeps the gutters clean, you need a lot of these: http://www.aebi-schmidt.nl/uploads/pics/Swingo_veegmachine.jpg
Most munis in NL clean all their gutters 5 or 6 times a year. Compared to other countries, I think that’s a very high frequency.
Having extensive cycleways and cycle lanes means that you have to sweep more often, anyway, to get rid of the glass. Glass tends to accumulate near the side of the road unless dispersed by car tyres, and on roads where cars rarely go near the kerb (or not at all, on cycle-only infrastructure) glass builds up. Dutch municipalities sweep busy cycle routes up to several times a week.
Well, as usual, amazing post. Most drainage grates here in LA that I encounter are the vertical and horizontal combination though they are much larger than the ones in your video. They don’t pose a problem for plain bike lanes but if we hope to someday see cycle tracks they could become an issue. Compounding the problem is that city street cleanings happen very infrequently here and only on some streets so leaves can often clutter up the drainage and cause flooding.
For some odd reason I blogged about the poor drainage in the early days of my blog
http://walkeaglerock.wordpress.com/2010/12/19/flooding-on-the-streets-of-eagle-rock/
I can’t help but to think how much better the city/county of LA could be for biking if we hadn’t spent $1 BILLION+ on expanding the 405 Freeway but instead spent that BILLION on creating Dutch quality bikeways and streets. Of course, expanding the freeway will do absolutely nothing to improve traffic in the region whereas spending even half that money on bikes could have changed the face of LA within a year.
Can you see why your posts always leave me so conflicted? I love your content and what it teaches us but it seems like we’ll never get there at the pace we’re going.
Keep up the fantastic work!
I still wonder how they keep those deep underpasses from flooding in case of severe rains.
Underground electric drainage pumps. In the street where my parents live one got replaced a couple of years ago. In the last decade it happened twice that the sewer system couldn’t cope with heavy rainfall and the toilets on the groundfloor overflowed with backed up water. The town decided to upgrade the drainage and sewer system. Newer wider pipes were installed and a new pump. Saw it been put under ground. It’s the size of a VW Golf and powered by the same electric network that powers the streetlights. This is in west Brabant by the way.
Here’s my atrocious example from San Jose, Californina. http://ladyfleur.wordpress.com/2012/08/09/bike-lane-fail-grateful-to-not-be-dead/
The good news is that after I complained, they replaced it with a better design within a few days: https://ladyfleur.wordpress.com/2012/08/16/bike-lane-success-newly-grateful-in-san-jose/.
Still, the in curb style is much better. We have those in my neighborhood.
Kerb drains do exist in the UK and offer a far better option where the road has been properly designed with self clearing gullies – these are where the 15-20 cm strip along the kerb is set slightly below the main surface and laid with setts or slabs running parallel with the kerb. Water flow is focussed in this strip so that when it rains the water clears the leaves etc down the hill. Drainage in the gully line catches the leaves and can stop the designed in clearing function
Best hardwearing road surface is stone setts with flat flush tops laid in a tight jointed bond on puddle clay or cold tar in times past, but modern systems also work. Stree near me has 160 years with minimal attention and still drains to sides – badly damaged in places by incompetent utility contractors and lack of council enforcing proper repairs.
Here’s a famously atrocious example from Dublin
http://goo.gl/maps/L0uLN
Yes that is actually a cycle lane.
Hundreds of people cycle through here every day, it’s one of the main arteries into Dublin from both bikes, cars and public transport. There’s also a large university close to here.