Laservision stop signs in Sydney road tunnels - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: August 19, 2021, 09:50:17 am
content: These kinds of systems have apparently been installed on Sydney roads for almost a decade, yet I only learned of them today.They are a "last ditch" effort in an attempt to stop over-height vehicles entering tunnels. You would think the plethora of warning signs, lights and flashing message boards would be enough, but apparently not for some drivers.Such a simple yet clever system.

author: SeanB
author_rank: Super Contributor
timestamp: August 19, 2021, 10:06:30 am
content: Bet there are still some who drive through that.

author: Berni
author_rank: Super Contributor
timestamp: August 19, 2021, 10:11:50 am
content: Oh nice one. Such a simple yet so effective solution. Mostly since it suddenly appears right in front of you, if you don't notice that then you might as well be sleeping at the wheel.The neat thing about it is that it can't damage anything since its just water. Deploying any sort of normal physical sign into the road like that would otherwise have serious safety concerns if someone hits it. In dense traffic id imagine a few cars get showered by it in order to display the stop sign soon enough to give the truck a safe braking distance.Opposite of the solution of the other internet famous bridge:They did add regular signs, but you can see the big metal pillars with cross bracing under it, so it makes sure the bridge can survive the sideways loads of anything the idiot divers throw at it. But this is not nearly as busy of a road, so i suppose an half hour to pull the truck out of there is not that bad.

author: CJay
author_rank: Super Contributor
timestamp: August 19, 2021, 10:22:09 am
content: Quote from: Berni on August 19, 2021, 10:11:50 amI bet people still ignore it, "didn't think it meant me"That can opener bridge was exactly the one that sprang to minds too, so many drivers are idiots

author: retiredfeline
author_rank: Frequent Contributor
timestamp: August 19, 2021, 10:31:56 am
content: I liked the irony of the phrase on the back door:

author: Rick Law
author_rank: Super Contributor
timestamp: August 19, 2021, 05:18:17 pm
content: Without a near-certainty of damage, some drivers will just take a chance instead of detouring to a longer and safer route. I was in a long traffic jam just over a weeks ago because one such "I'll be able to get through" truck driver was stuck under a rail bridge. I know there are ample well placed signs there since I frequently travel that route.I recall the tunnels between New Jersey and New York City had a rather good set up; may be it is there still. First are the warning signs, as one got close come the physical barriers. First is a structures with multiple heavy metal chains hanging down to the height limit. About 10 meter from entrance (if memory serves) is the second barrier has heavy metal chains now with bowling-ball size metal balls at the chain's end. The last barrier was a steel I-beam like structure about a meter from the actual tunnel.Now if you hit those chains, you are going to hear it. If you push on, you know the metal ball is going to do a number on your roof but still easy to get out. If you hit the I-beams, well, you are hopeless as a driver. I would have no issue if for those stuck under the I-beam, they have their license suspended for a duration - they have shown they don't care about safety or road signs.EDIT:adding thisBesides height, there is the weight limit.A bridge that just completed another major repair was near my home. Before it were multiple well placed sign on weight limit. This bridge is historic dated back to the 1776 revolution. Trucks didn't care about that either. We (Township with State help) spend good bucks repairing the bridge since it is historic - preserving the original stones where possible during the repair. Huge expenditure which I supported (by voting).This is not the first but the most recent repair already. Now added to the weight limit signs are "YOUR GPS IS WRONG: NO TRUCKS" and the added truck U-TURN space... There is no missing it. Hope this will stop them.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 19, 2021, 10:26:04 pm
content: Quote from: Rick Law on August 19, 2021, 05:18:17 pmThere's that (in)famous picture of a truck carrying a mobile home over a bridge that snapped under the weight, with it asking if that's covered by home insurance, car insurance, or roadside assistance.

author: thinkfat
author_rank: Unknown
timestamp: August 20, 2021, 10:08:42 am
content: Quote from: Rick Law on August 19, 2021, 05:18:17 pmAdding a narrow S curve designed to be impassable for trucks over a certain width and length might be good as well.

author: Cubdriver
author_rank: Unknown
timestamp: August 20, 2021, 03:17:33 pm
content: Quote from: retiredfeline on August 19, 2021, 10:31:56 am"On the road to success there are no shortcuts" ...but there are ARE low underpasses...-Pat

author: Rick Law
author_rank: Super Contributor
timestamp: August 21, 2021, 04:31:49 am
content: Quote from: thinkfat on August 20, 2021, 10:08:42 amWhat is added and how they are added often is left to civil engineers.What does surprise me is that they are not using as much modern electronics as they can.Height-limit should be rather easy to verify. Erect a couple of poles with photo censors on one and laser source on the other - determine if the beams are cut, than a sign "Height limit exceeded" with a whole line of blinking red lights should be rather easy to do. May be there are certain limitation/difficulty I am not seeing.Weight-limit is more difficult. Detecting weight would require adding different number of axles for the total. Deciding which axles is the first and which is the last from the same vehicle would be a more challenging tasks.

author: Bud
author_rank: Super Contributor
timestamp: August 21, 2021, 05:25:21 am
content: Quote from: Cubdriver on August 20, 2021, 03:17:33 pmI once saw on the road a tow truck pulling a wrecked Volkswagen Beetle, which had a painted logo on it that read " Lucky Bug Driving School". Yeah, I thought, how symbolic... hoping the student and instructor were OK.

author: Halcyon
author_rank: Unknown
timestamp: August 21, 2021, 05:47:06 am
content: Quote from: Rick Law on August 21, 2021, 04:31:49 amWhat you describe with the height sensors is exactly what happens here. They start several kilometres before the tunnel to give over-height vehicles an opportunity to take then exit(s) before the tunnel.Weight is determined by vehicle class so it's relatively easy to determine the maximum (legal) mass of a vehicle just by looking at it. This is unless of course the vehicle is over-laden which attracts severe penalities in itself. Heavy vehicles are randomly inspected and weighed along major arterial roads in Australia and failing to stop for these inspection is also an offence.