Lighting paths sensibly (an appeal?)

This article was published in 2012, in Newsletter 105.

The article by Martin Lucas-Smith, Lighting paths sensitively in Newsletter 104, has encouraged me to put some other ideas to paper. But first I should explain that Martin and I are different animals, he being essentially an urban dweller who also cycles irregular hours. I started work in the days when I had to clock in at 8.30am, and lived in a village. I’ve regularly cycled in the dark on totally unlit roads, and in peak hour traffic.

For the last few years I have had the luxury of cycling into Cambridge each day on NCN11 (the Genome or ‘stripey’ path) from Shelford, and more recently the ability to cycle all the way to the station without touching a busy road.

Of course that has meant riding on unsegregated shared-use paths with no proper lighting. NCN11 was equipped with ‘solar studs’ some five years ago. In the early days these were good enough to show any unfamiliar user the line of the route, and some said it seemed like flying down a runway. I’ve dim memories of those days. Now the solar studs are just as dim, with some failed completely.

They were never any good at highlighting pedestrians, especially those in dark clothing, or people on bikes with no lights, and one could be confused when meeting a bike equipped with cheap ‘see me’ LEDs that appear like just another ‘solar stud’. I’m aware of several crashes, including one that apparently resulted in a broken arm, and another serious enough to warrant attendance by an ambulance that could not get access.

Of course this path is a wonderful addition to the network, used for over one thousand trips each day, but some don’t use it in the dark, and the narrowness creates unnecessary conflicts.

So how can we do better?

I’m specifically thinking of urban fringe or very busy paths connecting to necklace villages. On these paths ‘personal safety’ worries deter some users, and others feel it necessary to invest in high-quality expensive LED lights for ultimate safety, which of course dazzle pedestrians or those with ordinary bike lights.

The recessed lights of the Cambridge Leisure Park are good at showing the way, but there is overall background lighting at all times, even if just from shops or adjacent roads. Such lights would also be expensive to fit along rural or semi-urban paths.

LED lighting from simple columns is the obvious solution. As 12 volt systems are available, the underground cables do not require the expensive protection required for 240 volt systems. LEDs are cheap to run and cheaper to maintain.

Although some of the locations I’m thinking of have floodlit car-parks, or floodlit all-weather playing areas, adjacent, I do think we could easily have a system that produces the minimum of light pollution consistent with safer routes.

Active lighting

Many houses have horrible halogen security lights activated by passive infra-red detectors, that cause even welcome visitors to be blinded and fall into beds of prickly plants. You will, I hope, be pleased to know that we can do better than that! We also have loop detectors that can not only spot bikes, but also determine the direction of travel. This means that with a few detectors, lights every say 50m, and a clever bit of control we could have lights that light our way, but only when people are present. I’m told that Sustrans is proposing something similar for a tunnel near Bath, but I’ve not unearthed details.

For busy routes such as the Busway paths from the station to Trumpington or from the Science Park to Histon, a better standard at peak times, with lights always on, could be the norm, and perhaps total darkness would be acceptable on all routes between say midnight and 6am.

Imagine cycling from the station to Trumpington on a late winter evening with lights turning on ahead of you and off behind you, and being aware that there was also a pedestrian in dark clothing ahead. If such a system exists, I’ve yet to find it, even though all the components are readily available.

Cambridge is a centre of innovation, and such a system would have wide application, not just on paths local to Cambridge. If you, or someone you know, can design a ‘bus’-based system, based on existing hardware, that could control such lights, please let us know.

Twenty years ago I was writing code for data-loggers to sample instruments on agricultural experiments in a similar way. If I could do it then, it must be much easier now. We’ve so much of our lives controlled by computers, not all of it good, but surely this would be good for vulnerable users on such paths, good for wildlife, good for reducing costs, and good for Cambridge?

Jim Chisholm