Honestly speaking, that's an incredibly difficult issue to try and optimize for. There are a ton of different measures you could implement to try and improve ambulance travel times, but they're the same street design choices that we know drastically increase accident rates and fatalities for drivers, cyclists, and pedestrians alike.
Wider travel lanes on normal streets? More signalized intersections with overrides for emergency services instead of roundabouts, stop signs, or other measures meant to decrease intersection accidents and fatalities? Removal of speed bumps, raised pedestrian crosswalks, etc.? Additional lanes so ambulances have space to pass other cars?
Sure, they could all ostensibly improve ambulance travel times. But they'd do so by dramatically increasing the number of fatalities on our streets. Not to mention the workload on those same emergency services. So while it can make sense to consider the impact on those services, they probably shouldn't be the driving factor. Or even a main one.
On the other hand, even if speed bumps and other measures cause minor delays, other changes might be able to balance them out. Dedicated bus lanes, for example, are basically exclusive express lanes you could choose to route emergency service vehicles down with potentially significant time savings.
In the Netherlands we have a completely seperated bus network. No speedbumps, traffic light priority and audible cue at the intersection. Works pretty well for emergency services.
Wider travel lanes on normal streets? More signalized intersections with overrides for emergency services instead of roundabouts, stop signs, or other measures meant to decrease intersection accidents and fatalities? Removal of speed bumps, raised pedestrian crosswalks, etc.? Additional lanes so ambulances have space to pass other cars?
Sure, they could all ostensibly improve ambulance travel times. But they'd do so by dramatically increasing the number of fatalities on our streets. Not to mention the workload on those same emergency services. So while it can make sense to consider the impact on those services, they probably shouldn't be the driving factor. Or even a main one.
On the other hand, even if speed bumps and other measures cause minor delays, other changes might be able to balance them out. Dedicated bus lanes, for example, are basically exclusive express lanes you could choose to route emergency service vehicles down with potentially significant time savings.