Hi. Ok.
I live in the desert, so it gets to 120 ambient. Inside the box would easily reach 180+ temps.
Lowest temps are around 20 degrees.
That’s why I was looking for a simple LED/Switch setup.

To use a pressure switch system still would not work with a timer since some drive slow & some drive faster, causing either premature clear, or prolonged waiting. What if they get a flat & have to change their tire 1/2 way up.
What about a counter?
Each person presses the button?
Example: Tom heads up, he’s almost to the top, Joe at the bottom sees it’s still green, presses the button & heads up. (2)presses, the top would wait for (2)presses to clear.

Why do you seem so sure that EVERY person that drives on this road is going to do EXACTLY what you want them to do?

That no one is going to simply not want to bother with rolling down the window of their nice, cool air conditioned car to punch a button? That, after punching the bottom when they enter the road, they are going to remember to punch it on the way out?

Or Tom punches the button and is the first -- and to his knowledge only -- car. But another car's coming up behind him that punched the button. So he gets to the top and punches the button. Nothing happens! He's expecting the light to go off and it didn't. So his immediate thought is that he must not have pressed it all the way, so he presses it again. Now it does what he expects, and the LEDs are off even though someone is still on the road coming up.

How many times is someone going to wait at one end because the light's red because someone didn't punch the button on the way out before they give up on the system and just ignore it completely.

How often is some just going to punch the button a bunch of times for kicks?

I’m sure that would need an IC chip, but maybe it would still be simple enough to stay cool & not be affected by the high temps?

If the temp is an issue for a timer IC then it is going to be an issue with a counter IC. The commercial temperature range on IC's goes up to 85°C, which is 185°F. That's for the junction temperature, which will be higher than the ambient. But you could mount a heat sink that sticks out the bottom of the box and is always in the shade. I'd use Industrial range parts which go up to 100°C (212°F).

One possible alternative would be to use radar sensors (that I think are becoming pretty cheap) at several locations along the road. Ideally you could have enough to cover the entire road, but that might make it too many. Then you could us their outputs to drive a simple display at each end that let's people know the status of the road usage. You might even be able to handle that flat tire scenario reasonably.

 

Lockout - I don’t think would be necessary. If they see red, they won’t press it until the last person up presses the button to clear the LEDs.

I think lockout would be advisable. What happens if A presses button, gets a green light to go up, then B comes along later (but before A has cleared the LEDs), forgets to press button, goes up? The counter will only count 1, but 2 will be on the way up.
How will you account for strangers not knowing the button pressing routine?

 

I think you all have excellent ideas!
I appreciate them all.

We all know each other.
We would follow the simple rule.
What to do will be posted.
It’s a locked road, so inaccessible to strangers.

 

Does someone coming up the hill always lock the gate behind them, or could sensing the status of the gate be used as a master reset?

ak

 

Yes. The bottom gate is supposed to be locked behind you, whether it’s (1)person or a group. They would lock it behind them & go up. There’s no counter & the gate is old.
The issues using the gate as the switch would be that you don’t know how man people are coming up or down, since there’s no gate at the top.