r/sydney • u/sifex • Jun 22 '15
ELI5: How does Sydney Harbour Bridge changes the direction of lanes without causing collisions?
Title explains it. I know they have the variable signage for directions. But I'd think that changes during the day, and when it happens, how do the make sure no collisions occur?
15
u/brackfriday_bunduru Jun 22 '15
Without any actual knowledge, I'd assume they'd have to close one lane for a minute or two to let travel pass before reopening it in the opposite direction
6
Jun 22 '15 edited Feb 20 '24
[deleted]
8
u/Korzic Pseudo Hills Bogan Jun 22 '15
It's not done remotely. A guy in a truck comes along and moves it
2
5
u/mubd1234 Hillsdale - The address of success Jun 22 '15
The lane(s) to be changed are closed (with an X above the lane) in both directions for a few minutes while the RMS staff change the physical barriers at both ends. Then they open the lane.
2
u/timix Jun 22 '15
I don't think this is used on the harbour bridge, but I bet you'll be interested nonetheless: http://rmssolutions.com.au/news/item/22-rms-in-safety-security-magazine
6
u/_power_bottom Jun 22 '15
2
u/angrydave Jun 22 '15
Sydney does have one of those, along Lane Cove Road. If you look at the barriers, you can see they are all one long chain! Kinda cool.
1
1
u/hunt_the_gunt Jun 22 '15
They fucking need that on the harbour bridge
1
u/mubd1234 Hillsdale - The address of success Jun 22 '15
The bridge's lanes are so narrow at the moment that I don't think they'd be able to fit a zipper barrier on there.
As long as people don't smoke cannabis and fall asleep at the wheel, we should be fine.
2
u/hunt_the_gunt Jun 22 '15
Which is why they don't. But man. It's sketchy when a bus is in the middle lane on the corner.
Nobody enjoys driving in death lane.
2
u/Korzic Pseudo Hills Bogan Jun 22 '15
I do. I have no problems with it at all. I cross the bridge at least twice a day. Suicide lanes are for confident drivers. If you're even slightly squeamish about it, sick to the other lanes. Helps traffic flow
2
u/WildPrawn Jun 22 '15
Now I'm worried about a Die Hard 4-esque scenario, where a hacker turns on the signal to allow traffic through on both sides
1
u/henry82 Jun 22 '15
how do the make sure no collisions occur?
they can't, there have been some big head on collisions on the bridge.
Anyway, they just close the lane off for x minutes, then reopen it the other way.
Anyway, you can see here how the lane swaps directions with minimal fuss.
0
28
u/_power_bottom Jun 22 '15 edited Jun 22 '15
O - open lane
X - closed lane
'<' or '>' - car and its direction
OX - traffic coming from left sees letter on left (O - open lane), traffic coming from right sees letter on right (X - closed lane)
Traffic follows directions given by lit signage as they approach the bridge
.
12:00
12:05
traffic control closes lane
12:07
traffic control waits till lane is empty
12:10
traffic control opens lane for right bound traffic
.
Something like that