Chisholm Trail: a vision revised

This article was published in 2014, in Newsletter 113.

Definition: Chisholm Trail A strategic cycle route that will extend along the rail corridor from Cambridge Station in the south of the city through to the Cambridge Science Park Station. (From Stop Press)
This ‘spare’ bit of Network Rail land could give easy access to arches beneath Coldham’s Lane bridge.
Image as described adjacent

I first wrote in the Cycling Campaign newsletter about the opportunities for a high-quality cycling and walking route through Cambridge in 1998, although the idea of such a route had been in my mind longer. I had moved to Cambridge in 1985, and as well as cycling around Cambridge I had also gazed out of train windows, and hence seen the possibilities.

Now, over 15 years later, with the first serious plans for some central sections being processed by county council officers, and some others expressing concerns over standards, I think it is time to review the situation.

When I first wrote, I thought that the most difficult sections would be getting under Hills Road and over the Cam adjacent to the railway bridge. And I did not think that we would have some excellent cycle routes on the fringes of Cambridge. The Cambridge Guided Bus route has enabled such fringe routes, as well as a route under the Hills Road bridge, and the Cycling Campaign worked hard with others such as Sustrans, at the public enquiry and later, to ensure good quality provision on those sections. Progress is even being made towards lighting the fringe routes, although there are flooding issues the Dutch would never tolerate. It is also clear that a cycle/foot bridge over the Cam on Ditton Meadows, near to the railway bridge, should soon be provided, and it may become the busiest cycle bridge over the Cam!

So what has happened to the ‘easy bits’ in the middle?

This underbridge on Coldham’s Common will remain an issue unless very large sums of money are available.
Image as described adjacent

Everything seems easy until you look at the details, but that should not dilute the vision. There is still the opportunity to create a route on both sides of the railway through much of central Cambridge, bringing easier access on foot or cycle to many facilities.

Crucial to this is using arches not occupied by railway tracks on both sides of Mill Road and Coldham’s Lane bridges. Both these roads are busy with motor traffic, and crossing them on foot or by cycle is risky or slow or both. Grade separation, by use of these arches, opens the routes for easier cycling and walking for a wider range of ages and abilities, as well as saving journey time.

Also crucial is using the planning system to ‘protect’ and enhance the route, both by restricting obstructive development, and by improving access along the route. This should further improve the permeability for cycling and walking, by linking residences, businesses, colleges, and open space.

Locations of points mentioned in the article
Image as described adjacent

In the longer term I still believe we can achieve such a route, and only on one section have I given up the long-term aspiration. For that one section the proposal was to use Coldham’s Lane and the ungated level crossing over the Newmarket line. In the past 15 years, with some good reason, Network Rail has become hyper-cautious over the safety of such crossings, and we also have the prospect of a more frequent train service on that line. A route over Coldham’s Common is the only alternative, and a sensitive approach will be needed here.

So what about those fiddles and wiggles that appear on initial plans?

A triangle of land on the Fen Road side of the river would make a good landing spot for the new bridge.
Image as described adjacent

If we want to cross from one side of the railway to the other we need to use an existing bridge or level crossing. At a bridge there is clearly a need to rise some five metres, which would mean two ramps each of about one hundred metres or use of an existing road. Just think about the length of the cycle bridge at the station. If such a diversion eliminates a busy road crossing, on average it may save, say a minute, especially if traffic lights are involved, which is equivalent to cycling about 300 metres. Many trips would be expected to cross the railway only once, with some not at all, once the full vision is realised.

crucial is using the planning system to ‘protect’ and enhance the route, both by restricting obstructive development, and by improving access along the route.

For a number of reasons the new Cam foot and cycle bridge is most likely to be on the downstream, or northern side, of the existing railway bridge, hence the level crossing at Fen Road is a special case. If you stand and watch here at a busy time, the existing conflicts are obvious. Queues of pedestrians, cycles and cars build up when the crossing is shut; then, when the gates open the conflicts are clear, as the crossing is narrow, and it is motor vehicles that dominate. Adding to this the numbers who might use the new Cam bridge would create even more chaos, and Network Rail would be likely to veto proposals that might make such a crossing less safe. In the long term there are obvious solutions here, but we all want a bridge in the short term. A link from the bridge, leading only to the Cam towpath, should solve that problem. With care it could also offer those residents of Fen Road on foot or cycle an alternative to the level crossing. Yes, such a route is probably 300 metres longer than the direct route, but won’t it be just as fast as waiting at the barriers, especially when we have more trains and they stop at the new station?

Network Rail

A route from Ditton Walk will be needed to construct the new Chesterton bridge over the Cam. Would not a route adjacent to the railway embankment also make a good final access route?
Image as described adjacent

Part of the land on the west side and much of the land on the east required for a good route is in the hands of Network Rail. Only an extremely small amount is obviously part of an operational railway, even allowing for the clearance of fences etc. from rail lines and OHLE (OverHead Line Equipment). Twenty years ago many would have expected carriage storage and cleaning facilities to move to Chesterton sidings, leaving space for housing and access. Kaleidoscope, much of CB1 development and the Clifton Road industrial estate were all originally railway lands. Now the land at Chesterton sidings has increased in value, meaning a move is less likely, which leaves a couple of pinch points where co-operation from Network Rail is needed. The maintenance facilities adjacent to Coldham’s Lane are far from modern and have poor access, so we may hope that changes will occur there. It also seems that various rail organisations are not familiar with ‘systems’ thinking. Like retailers, rail authorities seem to think customers who drive are more valuable, and hence huge sums are spent double-decking car parking or defending existing car parking capacity, when improving access for those on foot or bike might well be an easier way of increasing custom.

Enough of the route, more of the vision

My original article had a sub-heading: ‘super cycleway’. I’d like to retract that phrase… I don’t see this as primarily for 15mph+ riders going from one side of Cambridge to the other, but as a linear park, connecting to the surrounding streets with, where possible, green open space. The fast and confident riders might still stick to main roads, although I think many would have an equally quick, and far more pleasant trip, at a slower pace on the new route. More typical users are likely to be walking or riding a ten- to fifteen-minute trip that is free from cars on the road or parked on the footway. Walking or cycling with children to the school, park or a common would be more pleasant, with trips to the station or shops being shorter. The route must be suitable for an unaccompanied twelve-year-old. It certainly must not be a three-metre strip of tarmac with blind bends hemmed in by high palisade fencing, that can be so intimidating in terms of personal safety.

Economics counts

The route from Sleaford Street to the Beehive site would not be difficult to improve.
Image as described adjacent

Just as with sea and river defences, we need to show that spending is economically justified, and that the same money spent elsewhere would not produce greater savings. To do this at a basic level we need to add several components:

  • User benefits in terms of savings in time and money. This covers say a reduced cycle time from Kings Hedges to Addenbrooke’s, or from Trumpington Meadows to the Science Park. It also covers the savings of someone who converts from driving to cycling.
  • Non-user benefits. If one hundred drivers leave their cars at home and start to cycle, not only do they save money, but congestion is reduced so other drivers and bus passengers also save time and money. One hundred fewer peak hour cars peak on Milton Road would reduce the queue by around half a mile, and save all remaining users some five minutes of time. Reducing congestion even means a bus company can run more services with the same number of buses. Some costing systems ignore such sums, but in many major schemes these savings outweigh those of users. An early documented case was the construction of the London Underground’s Victoria line.
  • Health benefits.. There is an increasing recognition of the benefits of exercise. Cambridge residents are far more likely to cycle than those in Milton Keynes, and have far lower levels of obesity. More convenient cycle routes could further improve the health of Cambridge and South Cambridgeshire residents. In addition, air pollution caused by motor vehicles is now realised to cause significant increases in health problems, especially for those living, working, walking or cycling near to congested roads, so reducing congestion has health benefits for all.
Walking or cycling with children to the school, park or a common would be more pleasant, with trips to the station or shops being shorter.

The recent Riverside Bridge has double the predicted number of users, so it is clear that existing cycle traffic prediction methods are inadequate. If even just small numbers using that bridge previously drove, the overall economic benefits will significantly larger than predicted. It could be that the ‘non-user’ benefits for the Chisholm Trail will far exceed the ‘user’ benefits. Much recent work has shown that the returns from ‘small schemes’ are far greater than that from mega-projects such as the A14 upgrade.


Staged openings will occur, and the use of these early sections should demonstrate the value of having a high-quality route. The proposed river bridge will bring pressure to advance other sections, with the section under Mill Road giving a similar boost. With those two links in place, the benefits of the ‘2020’ vision will be obvious. Perhaps by that date we may have a route on both sides of the rail corridor for much of the distance between Hills Road and at least Coldham’s Lane?

Jim Chisholm