Monday, July 19, 2010

The Cambridge Guided Busway Cycle Path gets easily flooded

NOTE: The concrete tracks of the Guided BUSWAY should not be used for walking or cycling – the busway is fully operational. To use them would be extremely dangerous.

I like the Cambridge Guided Busway (CGB) cycle path. It provides me (and other cyclists and walkers) with a traffic-free, bus-free fairly straight route out of Cambridge in the direction of St Ives. I do think that the spending was over the top £100+million for a gravel cycle track is a bit expensive, although the route does have some even flatter concrete tracks for the more adventurous cyclist as well!

I do think that this route could have been even better at attracting more people on to their bicycles both for commuting and leisure if there had been more thought put into how locals might join the route and if the cycle path surface had had a decent tarmac surface along its entire length rather than just between Cambridge and Histon (and/or Longstanton). The distance from St Ives to Milton Road in Cambridge is around 20Km/12.5 miles and in cycling terms is a reasonable distance to commute, once you get into the swing of things. I accept that there will be some extra distance in either end but it makes a pleasant run and does not have to be cycled along every day. However for some reason planners do not seem to think that such distances are within the reach of normal people and so lit becomes more difficult to justify a quality cycle route if it is predominantly to be used for leisure. So we don't get high quality cycle rotue - so people don't use them which reinforces the view that people don't commute such distances. They ought to go and check out the Bath/Bristol cycle path (B&B cycle path), which is a 13 mile cycle path with a tarmac surface and a hill at the Bristol end.

I occasionally have to go to Bath for meetings and have taken my bicycle down and cycled the B&B path a couple of times. Here is a picture I took a couple of years ago (October 2008). In my experience the path is used by significant numbers of commuters. In fact according to Wikipedia it was used for 2.4million trips in 2007 with the number increasing by 10% per annum. (That number equates to over 46,000 trips per week and means an average over 6,500 every day of the week. The article does not discuss the average length of a trip and the demographics around the CGB and the B&B cycle path are different - but it suggests that our ambitions for cycle use of the CGB could have been and should have been greater. Although I accept that the buses will make the route less pleasant for cyclists and walkers when (if) they start running.

Here we have two cyclists on the CGB using the optional smooth cycle track - passing is difficult but it does allow two abreast each way for more sociable cycling. You have to be confident cycling along quite a narrow strip and try to avoid clipping your pedal along the edge of the track (or falling into the weeds in the middle). NOTE IT IS NOT REALLY A CYCLE TRACK AND SHOULD NOT BE USED.


I popped out on Saturday and used the CGB route to quickly head out of Cambridge so that I could then take a more picturesque route using various bridleways and byways back. There will be a two part Post discussing the journey following this post. However what surprised me is that the path up near the St Ives end seems to be very prone to flooding. we have had a bit of rain in the Cambridgeshire area - but pretty much every other byway and bridleway I have cycled along shows almost no evidence of rain as the ground has been so dry.

So i was surprised to come across this patch of recent mud on the CGB path - it is not advisable to cycle into sticky mud and muddy ruts unless you do it deliberately.



I was even more surprised to see that other parts of the CGB maintenance path were showing signs of the recent small amount of rain. This bit was even trickier to cycle through.



This is the same part of the track in closeup - it does not reassure me that this is a high-quality cycle path nor that the path is well drained. Indeed it suggests that the original calculations showing how few days the path might be expected to flood were woefully wrong - or the path has been built wrongly; either too low, the wrong surface or without appropriate drainage.



Although I did not cycle to St Ives, I turned off before the bridge over the River Great Ouse, there was a patch of path which had flooded across its width.



Some of the Council documents referring to the CGB talk about a high quality path - this is not it. I hope that they know why they got it wrong in the first place and that they fix it - properly. We should be seeing levels of use at least some way comparable to the B&B cycle path. Not a path that floods at the slightest hint of rain.


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  2. Please, just give us back our railway!

  3. Any news on the amusing story about 'ghost buses' making the traffic signals change as cyclists are increasingly attracted to use this luxury £150m cycle route. and they are triggering the signalised crossings at road intersections. The story has appeared in a bus industry magazine.

    Given the access options it could be quite a quick job to drop a single rail line thrown down on top of one of the beam-ways although it would be preferable to lift the beams out and off the supporting piles to lay a proper bed of ballast onto the formation that can be properly regulated without any risk of the beams underneath continuing to tip with ground movement

    The misalignment issue can also be seen in concrete slab roadways, and gave Brunel problems when he tried longitudonal sleepers on his first railway lines over soft ground. A small settlement at one end of a long beam is magnified by the size of the slab/beam to make a substantial misalignment at the opposite end - or a lack of supporting ground below and leaves the slab 'rocking' potentially stressed enough to crack or able to 'pump' the soil underneath into a fluid state which is not a good outcome.

    Perhaps a positive move might be to present a costed option for laying of a single rail line quickly over the formation to recover the heavy materials (beams) and leave a basic facility to shuttle a simple train back & forth. Edinburgh has a few trams to spare at present that could be towed back & forth.....

  4. I have to say it is rather nice when cycling along the concrete track to see the lights all change automatically and allow an uninterrupted cycle ride. If only all traffic lights were like that...

    It will be interesting to see how the tracks "degrade" over time when it is finally in use. I still think that the potential for oscillation in the "steering" guide wheels has been underestimated

  5. Hi Jamie, I am moving to bar hill and as I don't know Cambridge at all, is it possible to use the CGB to cycle into the Science Park? If so how long would it take a novice like me?

  6. Hi Tim,

    The simple answer is yes. The section of the CGB shared cycle path between Longstanton and Cambridge is due to have a tarmac surface laid when the Busway is up and running. (Cambridge Cycle Campaign Newsletter 88) At the moment it is ok, and you will be able to avoid the really rough bit at the Milton Road end.

    Here is a Bike Route Toaster link to the route I would take. It is 12.8K/8miles long which at 12mph is about 40minutes. It does have a brief climb and the worst bit of the route is the road between the A14 junction and the CGB near Oakington which is probably a rush-hour rat run. You could take a slight detour along NCN51 along the Cambridge Road and then up the Park Lane Cycleway. You might also want to check the Cycle Streets website which has a cycle-specific journey planner. I tried it out and it gave these suggestions.
    There are three suggestions Faster, quietest and balanced. In this case the balanced and quietest are the same and follow some bridlepaths in the early stages avoiding Dry Drayton. There is no way I would use the fastest route, it runs along the A14. I have cycled along the A14 but aside from the danger it is way too noisy. You get a set of turn-by-turn maps and some photographs. Their estimate is 7.5miles and 43minutes and you save 2.24Kg of CO2.

    I think I ought to give the Cyclestreets planner a test run and write about it. The information provided looks very impressive.

    1. I use the CGB daily to travel to College. It is very good, apart from the mornings, people are standing up, right up to the doorway. This morning we were having to get off the bus just to let one person make their way off the bus.

      I am making a documentary film for a college project about 'cyclists v motorists' in Cambridge. I know it is a never ending debate, however if anyone has an interest in the topic, I would love to speak to you or even film an interview with you for my documentary film.

      You can contact me and track my progress with the film on my facebook page

  7. I appreciate this is an old article now, but just want to warn anybody unfamiliar with the Busway that it is now fully operational and you ABSOLUTELY UNEQUIVOCALLY CANNOT ride on the concrete tracks (described as the 'optional smooth cycle track') as the couple in the second picture are doing, unless you want a high-speed double-decker in the face. The proper cycle route running alongside is now in pretty good shape and is the ONLY safe way to ride this route.

    1. Thanks Laura, I have added a warning at the start of the post. The shared-use tarmac path alongside is in good shape, but readers should also be warned that it can flood in places near the St Ives end and be impassable. Usually there are signs indicating such on the route.

    2. Wow, you're quick!! Thanks, frankly I got a bit queasy even looking at that picture despite knowing the line was closed at the time!! Disappointing to hear that the St Ives end is still ropey though!

  8. Update 2014... Still can't get to St. Ives as you have to cycle through a duck pond - shortly after a large barrier saying "Flooding"... The cycle path surface (under the ducks) is great though :-(

    1. is a good website for up to date info you can also find it on My Blog List up to the right of this page. The comments on that Blog will quite often provide the most recent info.


  9. Hi, can anyone confirm how much of the busway path is flooded between St Ives and Swavesey at the moment? Planning to cycle to work later this week but more rain will scupper that. Cheers