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.