Wrong-way driver warning systems

[kphoger]

Why can we not just install tire slashers on on-ramps?  Especially HOV on-ramps which, at least in Washington, seem to cause the most confusion.

Well, you'd need the tire slashers on the off ramps to prevent the wrong way drivers... 

But in actuality, those are not really designed to be taken at speed, which is why you only really see them at places where you expect vehicles to be driving slowly anyway (like exiting a pay parking lot). And there may be some cases where a vehicle may need to legitimately travel in the wrong direction on an off ramp–maintenance vehicles, emergency evacuations, etc. And I imagine the DOT would be at fault if for any reason the devices punctured tires of a driver actually going the right way, so there's probably potential liability issues as well.

This is why they would remain fully retracted until a wrong-way driver is detected, then deployed.  Better the cost for paying for new tires, than being sued for allowing a wrong-way driver onto the road.

I'm trying to imagine how this plays out...

1.  Driver inadvertently starts up the off-ramp.
2.  Detection system notices wrong-way driver.
3.  Tire slashers are deployed.
4.  Driver runs over tire slashers.
5.  Vehicle becomes inoperable in the middle of the off-ramp.
6.  Trucker exits the highway at 60 mph.
7.  (This does not end well.)

[jeffandnicole]

Why can we not just install tire slashers on on-ramps?  Especially HOV on-ramps which, at least in Washington, seem to cause the most confusion.

Well, you'd need the tire slashers on the off ramps to prevent the wrong way drivers... 

But in actuality, those are not really designed to be taken at speed, which is why you only really see them at places where you expect vehicles to be driving slowly anyway (like exiting a pay parking lot). And there may be some cases where a vehicle may need to legitimately travel in the wrong direction on an off ramp–maintenance vehicles, emergency evacuations, etc. And I imagine the DOT would be at fault if for any reason the devices punctured tires of a driver actually going the right way, so there's probably potential liability issues as well.

This is why they would remain fully retracted until a wrong-way driver is detected, then deployed.  Better the cost for paying for new tires, than being sued for allowing a wrong-way driver onto the road.

You may also want to include a tar pit.

So...what normally happens when a car tire blows out?  There's an instant loss of control of the vehicle.  The vehicle may start swerving over the roadway.  It's bad enough when this happens on a highway where everyone goes the same direction. When this happens on a 2 way roadway, or on a ramp entering the highway, now you're setting up for a head-on collision.

So...what happens when there's 4 blown tires on a vehicle going the wrong way when traffic is headed right at it?  Again...that will not end well either.

Also, how is a transportation department sued for "allowing a wrong-way driver onto the roadway"?  They didn't "allow" anything.  There is usually signage around the ramp indicating that it's for the opposing direction.  Even minimal signage is sufficient enough, even if it falls short of what the MUTCD calls for.

[echo]

Although not a response based system (but rather a signage bridge assembly), the Ville Marie Expressway/ Autoroute 720 in Montreal uses a (what I assuming is a) hybrid fiber optic static display with the No entry symbol combined with a pulsing "Entree Interdit"  (Entry prohibited), The first link below is the off ramp from 720 Oust/ West to Saint Marc and the second being off ramp to Rue De La Montagne. Perhaps for a non-native of Montreal the assemblies do grab your attention, though I'm assume they just become background noise with time.

https://earth.google.com/web/@45.49118566,-73.57755662,46.78881073a,0d,60y,148.1542h,90.8828t,-0r/data=IhoKFms1SGpsZmFtcEM1emtPS1ZRMFFsTGcQAg?utm_source=earth7&utm_campaign=vine&hl=en

https://goo.gl/maps/7Sipdcp6EfzwMZsk6

On Caltrans marking of the off ramps with the do not enter stripe for opposing traffic, I feel they took some inspiration from the aviation sector; any taxiway crossing a runway (short of encroachment limits) is typically striped white on red with the runway numbering and/or ILS. Curiously for high speed turnoffs (typically no more than a 30 degree angle) at airports not under FAA regulation, a no entry stripe is utilized.

[Katavia]

https://goo.gl/maps/2XBWbHn9YPqkr7ib9

Yellow-and-black "TURN AROUND" sign beyond usual "WRONG WAY" sign at I-40 Exit 214/Wendover Avenue in Greensboro.

[fillup420]

the NC 540 toll road has light-up wrong way signs at toll gantries, although it seems like its a bit too late to be warning the wrong-way drivers...

https://www.google.com/maps/@35.7924381,-78.888893,3a,41.3y,357.04h,86.56t/data=!3m6!1e1!3m4!1s39IoYMNJfBhBBJbqo1HncA!2e0!7i13312!8i6656

[machias]

Back in the 1970s NYSDOT used to install "DO NOT ENTER" / "WRONG WAY" at the top of an exit ramp and "WRONG WAY" / "GO BACK" half way down the ramp. Both sign combinations were installed at a 30-ish degree angle to the ramp and on both sides of the ramp. The signs were fairly large. Why did this practice stop?

The installations I'm thinking of had Do Not Enter "hamburgers" instead of a circle with a barrier in the middle of circle like we see today.

Does any state still use "GO BACK"?

[ErmineNotyours]

the NC 540 toll road has light-up wrong way signs at toll gantries, although it seems like its a bit too late to be warning the wrong-way drivers...

https://www.google.com/maps/@35.7924381,-78.888893,3a,41.3y,357.04h,86.56t/data=!3m6!1e1!3m4!1s39IoYMNJfBhBBJbqo1HncA!2e0!7i13312!8i6656

For drivers making U-turns to avoid paying the toll?

[UCFKnights]

https://goo.gl/maps/2XBWbHn9YPqkr7ib9

Yellow-and-black "TURN AROUND" sign beyond usual "WRONG WAY" sign at I-40 Exit 214/Wendover Avenue in Greensboro.

And the poor placement has them centered between the drivers going the correct direction and the incorrect one... 

the NC 540 toll road has light-up wrong way signs at toll gantries, although it seems like its a bit too late to be warning the wrong-way drivers...

https://www.google.com/maps/@35.7924381,-78.888893,3a,41.3y,357.04h,86.56t/data=!3m6!1e1!3m4!1s39IoYMNJfBhBBJbqo1HncA!2e0!7i13312!8i6656

There appears to be a small access road right before it for the maintenance workers to park for the toll gantry... its probably to try to alert them if they make a wrong turn when returning back onto the highway?

[index]

Here's this system National Sign & Signal has for that:
https://www.youtube.com/watch?v=vJ92OZCUVPw
On the topic of wrong way spikes...Colombia has that covered. At least it looks like it.

http://prntscr.com/wfk29j
http://prntscr.com/wfk3l6
Disclaimer: I am not taking a side by posting that.

[CoreySamson]

I posted this in the "Strange Arrows On Pavement" thread a couple of days ago...

The reflectors look a lot like something I've seen used a lot on exit ramps in my area, except these are located much closer to the gore sign, so it's more clear what's going on. I believe they exist to combat wrong-way drivers at night, as the back of each reflector is red. The dumb thing about these is that even though they've all been installed in the past couple years, the glue that holds the reflectors to the tarmac doesn't appear to be that durable (something to do with the heat?) and many of the reflectors get jarred loose by cars running them over, so I don't like them too much.

Is this common practice elsewhere in the U.S?

[PurdueBill]

PA has been known to use ENTER HERE in places as well, but I don't know if it is really a wrong-way prevention measure or just a traditional supplement at an entry intersection with lots of islands and dividers.

The Mass Pike used to have flashing red lights at the wrong-way facing directions of entrances at rest areas, mounted on a streetlight pole.  Most are still around, but I don't know how effective they would be for someone not paying attention.  It's probably a little more effective with the WRONG WAY or DO NOT ENTER sign still there. 

[roadfro]

I posted this in the "Strange Arrows On Pavement" thread a couple of days ago...

The reflectors look a lot like something I've seen used a lot on exit ramps in my area, except these are located much closer to the gore sign, so it's more clear what's going on. I believe they exist to combat wrong-way drivers at night, as the back of each reflector is red. The dumb thing about these is that even though they've all been installed in the past couple years, the glue that holds the reflectors to the tarmac doesn't appear to be that durable (something to do with the heat?) and many of the reflectors get jarred loose by cars running them over, so I don't like them too much.

Is this common practice elsewhere in the U.S?

Those reflectors are patterned after the MUTCD one-way pavement marking arrow. Not sure that doing this with reflectors is common.

I believe Nevada DOT has a detail for it in their standard plans with reflectors. But I can count on zero hands the amount of times I've seen a one-way pavement marking in Nevada, let alone one done with raised pavement marker reflectors.

[Flyer78]

The Thruway has a small blurb on their Innovation page (http://www.thruway.ny.gov/oursystem/maintenance/innovation.html) that describes LED signs activated by Doppler.

Image from linked section:

[PurdueBill]

Here's this system National Sign & Signal has for that:
https://www.youtube.com/watch?v=vJ92OZCUVPw

Their web site has nothing but a broken link about it (a press release from 2013; wonder if it didn't sell well?); did it only activate when traffic came up the ramp the right way or would it flash when something came the wrong way too (I hope so)?  The latter is when it is needed much more; when no oncoming traffic is around to indicate that you are going the wrong way before you enter the mainline.

[stevashe]

One-off, oversized, overhead Wrong Way sign.  This is over an old alignment of road that is now an offramp, and needs to be seen in snowy conditions.  The sign next to it also said Wrong Way according to older Street Views, but has faded.

Here's what it looked like last weekend, with the crazy amount of snow up there right now that really is the only warning you get!



It's not quite a one-off though, the offramp to Mercer St in Seattle has the same thing.