4 ms·

Those are not the same at all. Search for "swept path analysis" for just one component of what you're missing. (There are many other components of design of a

Those are not the same at all. Search for "swept path analysis" for just one component of what you're missing. (There are many other components of design of a curve like this to consider.) A 90 degree change in direction is fine by itself provided there is sufficient radius for vehicles to make the turn at the design speed. In this case, if its two lane you may not be so convinced of its safety when it's your loved one on a scooter who got hit by a bus which tracked over into the oncoming lane just to navigate the curve. Or if its a single lane, when they died on the ambulance which was stuck in traffic on the bridge because two vehicles are unable to pass and everyone behind them would need to backup in unison to sort out the resulting cluster. But safety is only part of the duty to the public here. The bridge needs to function for its intended specification and if it fails to do so for basic engineering reasons, you absolutely have no business holding a license and signing off on public plans and indeed you would be disciplined or stripped of your license for something like this.

freetinker 1y ago
An elegant solution to this problem would be to enforce a very low speed limit entering the turn. “Sharp turn ahead, reduce speed to 5 km/h”
- Enginerrrd 1y ago
  Even if the swept path issues were not an issue here, that method has been tried and tested, doesn't work, and is considered bad design practice in the field of traffic engineering. There's a great deal of evidenced backed engineering practices and solutions to draw from to solve issues like this. Unlike software in noncritical applications, you can't just pull things out of a hat and hope it works. People die if you do that. You can't just say "here's how fast you can drive this road." You have to design the features of a road to calm traffic. If you design a road like a freeway and then put up a 15mph speed limit sign, people aren't going to just drive 15mph. Thats just not how traffic and people work. If you want people to go slower you should design traffic calming features into the road. Its generally bad to have inconsistent design speed for different features of a road. And by bad I mean people will get killed at disproportionate rates. It happens all the time anyway for various reasons but not very often.
- potato3732842 1y ago
  Completely ignoring that the point of the bridge was to move a fuckton of traffic and saddling it with a restriction that makes it unfit for purpose if the users behave lawfully is not elegant. It is ignorant to the point of not being distinct from malice. It's like an adult version of one sibling being told don't touch the other and then they get in the others face while saying "I'm not touching you".
  - FinnKuhn 1y ago
    Agreed, the bridge is definitely not fit for that purpose. It's still not dangerous though unless you take spiking heart rates caused by bad traffic into account. ;)

freetinker 1y ago

An elegant solution to this problem would be to enforce a very low speed limit entering the turn. “Sharp turn ahead, reduce speed to 5 km/h”

Enginerrrd 1y ago
Even if the swept path issues were not an issue here, that method has been tried and tested, doesn't work, and is considered bad design practice in the field of traffic engineering. There's a great deal of evidenced backed engineering practices and solutions to draw from to solve issues like this. Unlike software in noncritical applications, you can't just pull things out of a hat and hope it works. People die if you do that. You can't just say "here's how fast you can drive this road." You have to design the features of a road to calm traffic. If you design a road like a freeway and then put up a 15mph speed limit sign, people aren't going to just drive 15mph. Thats just not how traffic and people work. If you want people to go slower you should design traffic calming features into the road. Its generally bad to have inconsistent design speed for different features of a road. And by bad I mean people will get killed at disproportionate rates. It happens all the time anyway for various reasons but not very often.
potato3732842 1y ago
Completely ignoring that the point of the bridge was to move a fuckton of traffic and saddling it with a restriction that makes it unfit for purpose if the users behave lawfully is not elegant. It is ignorant to the point of not being distinct from malice. It's like an adult version of one sibling being told don't touch the other and then they get in the others face while saying "I'm not touching you".
- FinnKuhn 1y ago
  Agreed, the bridge is definitely not fit for that purpose. It's still not dangerous though unless you take spiking heart rates caused by bad traffic into account. ;)