Flashing your headlights at temporary traffic lights

For example one evening last week (it was still daylight) we were out and about and while driving through a local village we came across some roadworks. As we approached the temporary lights you could see that there were no cars waiting on the other side so he starts flashing our headlights and in a few seconds the lights turn green.

I've seen similar symptoms, but the cause is I suspect different. In some of the semi-rural areas around here you can see lights that settle on all-red when there's no traffic about, and then change to green for approaching traffic pretty much as it arrives - but triggered I'm sure by the Doppler system that Mike described.  It would be an interesting to repeat your partner's experiment, under the exact same conditions, but without flashing headlights and see if the change the same anyway - I suspect they would.

  - Andy.

In fact I wouldn't be surprised if it appears to work quite often, as it's quite likely that due to the time before the driver gets bored and starts flashing their lights is very similar to the time interval chosen for the crossing change (because it needs to be short enough to not cause an impatient driver to jump the lights).

Something I’ve seen widely used in France is a countdown timer at temporary lights so you can see how long you have to wait. Love that idea!  Stops people getting frustrated as they know exactly how long there’ll be there for. It’s kinda like how they now have more info at bus stops so you know how far away the bus is and also on the train apps too. So you’re not always wondering if it’s going to turn up . I’d love to see the countdown timer approach being adopted here in the UK as well. May also stop people from jumping those red lights and causing havoc at the other end if they knew the sequence changes every 2 mins or so. 

Plus 1 for that idea of count down timers on temporary traffic lights for the UK

Interesting - I do a lot of work on improving safety at level crossings (road / railway crossings), where we have big issues with impatient crossing users doing silly (and sadly occasionally fatal) things, I'm wondering if there's something in that idea that we can use - I don't think we could use a countdown timer as such as there's always a chance of the train stopping as it approaches the crossing which would throw the time off, but there may be something - I might throw it in next time we're brainstorming ideas!

This is true engineering.  People having open discussions and making things better for everyone in general.  

This is true engineering.  People having open discussions and making things better for everyone in general.