Portugal's Velocidade Controlada – speed control traffic signals

When I travelled through Spain back in '99 these were pretty common. They usually turned green when cars had slowed down to the speed limit. I travelled by bike so I didn't trigger them very often..

> Robocars of course would know where all these are and never trigger one, even if the occupants have commanded the vehicle to exceed the limit.

I will be very surprised if occupants of self driving vehicles have that option.

Sounds a little bit like (though more sophisticated than) the timed lights that some cities employ, for example Oak and Fell streets in San Francisco. If you go the speed limit you'll get green all the way though; if you speed you'll just sit at a red light.

Portuguese here. Speed cameras are definitely legal, although it's mandatory to have a sign indicating their presence x meters beforehand (if I'm not mistaken). Also mobile police units with speed cameras in very discreet places is a common thing. What happened in Lisbon some time ago though was that most of the radars ended up dying due to lack of maintenance (due to lack of funds/attention/whatever). A lot were recently reactivated I heard.

But yeah these speed sensitive red lights are common and I agree that they work pretty well. Social pressure is good for behavioral nudging. Reminds me of those led signs that show a sad face if you go over the limit on certain residential areas for example.

However I must say that nothing beats Belgium in speed radars. Especially in Flanders, there are so many of these damn Gatso speed traps... What really makes the whole thing work though is a very good system behind it. Here in Belgium, if you're caught by a speed camera, you'll get the fine within 2 weeks tops. In Portugal however you might not even get it because the pile of fines to process is too big and the system isn't prepared for it.

I can confirm the roundabout obsession too :) those can be really annoying but they sure slow people down.

Oh they'll get you speeding on photo radar alright. The question is if the fine will actually get to you before 3 months because the system is so poor. And then you ask for the photo evidence and they'll tell you that you have to pay for it (this happened to me once).

Fines for running red lights are an instant very serious offense and two of these will suspend your license. Speeding depends on how much you went over the limit but it's a bit more flexible.

4-way stop signs are the stupidest idea when there is very little traffic or when there is a lot of traffic in a given intersection. In fact, they only work well in a moderately trafficked intersection; vehicles are supposed to stop once and then go through the light.

Roundabouts solve this entirely because for low, medium and even high congestion areas they are very effective at clearing out traffic. Sure they are definitely harder to tackle but as long as you're not in Braga (go around the outside or you'll crash into someone) you will have little to no issue doing them as most people are civil enough to tackle them properly. The issue is placing them because they require significantly more space and not all locations are suited to having them; if you notice most new planned roads all include roundabouts.

No, that's different. This light is normally green, and only goes red, briefly, if you speed on the way to it. The rest on red stays red, and goes green after you slow down a bunch for it.