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Comment by MichaelZuo | Hacker News Reader

Having to stop traffic, and then redirect it into the one emergency lane, every time 100m is finished in order to advance seems like a huge disadvantage.

If the road is anywhere close to max capacity this will cause traffic jams either way.

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But usually roads aren't even close to max capacity at night, when the shifting happens – which, I imagine, is much less stressful and time-critical than doing the whole resurfacing in a single night.

It would be awesome if the the entire bridge could slowly move as one while traffic keeps flowing over it. That would require far more and far bulkier wheels than the current ones designed to carry only one support segment. That will have to remain the stuff of fantasies...

The bridge could temporarily lift just the 2 ends and traffic could continue slowly under the bridge while the bridge moves ahead. However, it needs to also raise its height for trucks to pass under or alternatively, trucks could be temporarily suspended/rerouted from the road while the bridge moves.

If you look carefully, it seems that it can. It has wheels, and it's probably motorized.

It had wheels and it can move. But only with traffic shut down.

Sure, but that can happen at night with minimal disruption to traffic as it takes only the time to move it, not the time to disassemble, move, and re-assemble.

Traffic is currently redirected into the emergency lane 100% of the time, so this is still an improvement.

hence why the work requiring the stopping and redirecting happens at night.

They can only complete 100m once every 12 hours?

with minimal road disruption, though.

at least where I live you'll often seen lane reductions measured in weeks for repaving.

I've seen projects to pave only a few miles take years. Not even roads that are that busy, even.

That doesn't sound right, assuming a lane width of 3.5m, they can only resurface roughly 29 square meters an hours?

With all that equipment and manpower.

you need to scrape all the way to the base and then fill back in when repaving. and you also can't lay asphalt in rain.

I would think that merely repositioning can be done overnight.

I was under the impression the bridge rolled forward as the works continue.

Possibly, but unlikely IMHO - it looks like the bridge deploys rigid hydraulic outriggers when stationary, and changes to flexible pneumatic tyres when moving.

If the bridge was supported by flexible rubber tyres while heavy trucks were driving over the top of it, it'd probably wobble enough to make everyone involved uncomfortable.

I don’t think ragebol meant that the bridge rolls forward with traffic on it. Just that once a 100m long stretch is finished they can roll the bridge 100m forward with the traffic re-routed or suspended during the repositiong. If they time it right the resurfacing can be done with minimal disruption in the dead of night.

Half right. At night, they direct all traffic onto the shoulder / emergency lane and roll the bridge forward 100m with no traffic going over it at the time. By day, the bridge is stationary, traffic goes over it, and work goes on underneath.

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