> Just tell that to all the cyclists going < 20mph in 40-50MPH roads
That's again a 20-30 speed deferential, not to mention a huge difference in weight. We're talking about a 5-10 one between cars.
Also, if it's a heavy freight truck going 20 in a 40mph single lane. yeah, no issue at all with that speed deferential isn't there? Maybe the problem is here the inattentive, impatient drivers plowing through the cyclist?
> acting in capacity to react in an emergency is more about following distance than speed
The cars in front are not the only hazards.
Overall, I think you're making it too extreme. I'm not saying you should be going 20 on a highway. I'm saying going 5 under a posted speed limit is actually very reasonable, and it's what self driving cars (and human drivers) should do. It will reduce crashes. I think we disagree there.
> Maybe the problem is here the inattentive, impatient drivers plowing through the cyclist?
It's not just cars that become inattentive, and I agree the ultimate fault of those accidents are with the operator not paying attention. I've have cyclists swerve in front of me pretty close seemingly unaware I was there as they cut over for a left turn at the last second without signaling. Or cyclists blast through an intersection without stopping despite me already properly starting to go through the intersection. It's not like only people in cars make mistakes. However, speed differentials still increase risks. Reducing speed differentials and encouraging everyone to go about the same speed is better than having a mixture of speeds in the same traffic flow. Mixed speeds cause friction, friction increases the likelihood of accidents.
> Also, if it's a heavy freight truck going 20 in a 40mph single lane. yeah, no issue at all with that speed deferential isn't there?
No, there's still the exact same issues with that speed differential. People bunching up, lots of changing lanes, differences in speeds, etc. Sure, sometimes equipment needs to take roads and just can't or can't safely operate near the posted speed limit. I'd still say that equipment is causing more traffic flow issues, and thus more chances for accidents, being a slow member in traffic compared to all the other cars going about the same speed as each other. But they do have a right to use the roads, and I do agree people just need to deal with the disruption and be better operators around those obstructions. In the end there's still little excuse for cutting people off and changing lanes without watching, but if they never had to change lanes...
> I'm saying going 5 under a posted speed limit is actually very reasonable,
Going 5 under can be reasonable, I agree. There are lots of instances where one can do it safely, and increase the safety of those around them. If I'm driving down a residential street posted at 30mph but there's a high likelihood of pedestrians popping out from around parked cars, I'll drive under the speed limit, often 5mph+
I definitely disagree that individuals should subject themselves to a hard rule of always driving 5mph under the posted speed limit though. It all depends on what's the reality of the situation at the moment. If everyone is already going well over the posted speed limit, going well under it isn't going to increase overall safety. If the roads would benefit from traffic going slower, the speed limit should be changed and the road should be modified to encourage lower speeds.
If the roads should be 5mph slower, we should redesign it so everyone goes slower, not just some small percentage of cars while everyone else blasts past without immediate consequence.
Could a lot of our roads be safer if we redesigned them to make people drive slower? Sure. If I cause traffic congestion and drive in a way that's outside other driver's expectations I'm not making things safer though, I'm causing problems.
That's again a 20-30 speed deferential, not to mention a huge difference in weight. We're talking about a 5-10 one between cars.
Also, if it's a heavy freight truck going 20 in a 40mph single lane. yeah, no issue at all with that speed deferential isn't there? Maybe the problem is here the inattentive, impatient drivers plowing through the cyclist?
> acting in capacity to react in an emergency is more about following distance than speed
The cars in front are not the only hazards.
Overall, I think you're making it too extreme. I'm not saying you should be going 20 on a highway. I'm saying going 5 under a posted speed limit is actually very reasonable, and it's what self driving cars (and human drivers) should do. It will reduce crashes. I think we disagree there.