I'm planning a ride (Strava route) in the Alps, and I know there are some tunnels in the area. Coincidentally by taking the old road I'm planning to avoid the ones I know about.

I'd like to have a decent amount of rear light showing when I enter the tunnel, but don't have enough battery to have it running all day (it's a 200 km ride). I'm also not likely to be able to find a safe place to pull over and turn on a rear light when I know there's a tunnel coming up. So in an ideal world I'd run my high-power rear light for any stage of the route that has tunnels (and I'm likely to be stopping reasonably often). The front isn't an issue as I can switch that while going along, but my (good Lezyne) rear light is in a fiddly place and has a fiddly switch requiring a long-press. I'll have a back-up on my helmet that I can easily press while going along but can't confirm that's on while riding.

Cue sheets from Strava and Google Maps don't mention tunnels, and so far I've been following the route in one window and examining it on OpenStreetMap in another. If I plan further rides while I'm out there, I'll only have a small screen to check, and some are subtle or hidden under place names. Is there a better way?

  • 1
    Is there any scope for putting the Lezyne in a less-fiddly place? Alternatively, would you be comfortable running it in blinky mode? They last forever, that way. Jun 15, 2018 at 13:00
  • Perhaps you should look into getting lights that are less bright but last longer, and possibly wearing reflective clothing. My rear light is only 20 lumens but is plenty visible in low light situations. You could even use 2 or 3 of them. They are rated for 25 hours even when not flashing, or up to 76 hours in the strobe mode. I would hope that drivers had their headlights on in tunnels, and proper reflective clothing will be as bright as their headlights.
    – Kibbee
    Jun 15, 2018 at 13:12
  • @Kibbee I have a wide range of lights, so don't intend to buy any more. The really long-lasting ones are permanently fitted to my pannier racks, which I won't be using
    – Chris H
    Jun 15, 2018 at 13:37
  • @DavidRicherby I might well do that. I had hoped for it to be addiional
    – Chris H
    Jun 15, 2018 at 13:43
  • 1
    You could request it as feature for brouter (my favorite bicycle router). I wouldn’t be surprised if he adds it.
    – Michael
    Jun 15, 2018 at 17:37

2 Answers 2


None of the bike routing services I have tried or asked about know about tunnels. They don't even mention them on route/cue sheets (unless presumably the road name has "tunnel" in it) so a text-search fails too. When it comes to scanning the route for tunnels, OpenStreetMap (standard or humanitarian layer) is clearer when zoomed out to a reasonable scale than Google maps or OpenTopoMap.

If you like watching video and your route is on Google Streetview, this video player for Streetview (link is a section of my route) will indicate tunnels, but it takes more patience than scrolling through the route.


I did a quick google about that, and google maps does not offer that feature. The only way to check it to zoom in the map and look for grey road sections.

Here is a list of "named" tunnels in the alps.; I assume they only list the longer ones.

List of Alps Tunnels

What you will see most are small hill-side tunnels to prevent rocks falling and avalanches. Those are usually relatively small, and often open on one side.

In those cases, no need to open your rear-lights (IMO).

Avalanche tunnel in Spain

  • I know I'm avoiding some slightly longer ones where I would really want the light. The contrast from bright sunlight to dark tunnels has a big effect on visibility
    – Chris H
    Jun 15, 2018 at 12:59
  • Actually those avalanche tunnels can be really nasty if they're partially open on the sunward side -- it's like strobe lighting inside (and note that the example I've linked isn't straight, in common with many of the tunnels in the area, including fully closed)
    – Chris H
    Jul 11, 2018 at 15:31

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