I know of four ways on how to light a bicycle tunnel so that users can safely pass through.
- The obvious – find electricity somewhere nearby, run a power cable and install electric lights. Since most tunnels are wet, special care must be taken to use water proof lighting fixtures, and control boxes. It is strongly suggested that the control box not be in the tunnel.
- The second obvious is use solar power. Involves solar panels, batteries, and led lighting. This has a larger front end cost, but has close to zero maintenance cost.
- There are commodity led spotlights that are motion sensitive. They cost in the range of $20 to $30 per unit. Putting them on the walls at appropriate intervals, gives the user a traveling pool of light as they go through the tunnel. They typically run on standard alkaline batteries that depending on traffic would have to be replaced one year of so. The spacing is dependent on the particular light purchased and placement height.
- If you have a short straight tunnel that is paved, then highway reflectors can be used. Place three rows on the trail – at the edges and in the center. In addition a row on each wall about three feet up may also be placed. With this configuration often the sunlight is enough to provide guidance. This approach has been used on longer curved tunnels, but that requires the user to have some sort of light. Even a feeble light will provide guidance.