On 22/02/2018 21:42, dennis@home wrote:

You aren't holding up traffic if you are travelling at the maximum safe
speed or the limit (whichever is lower).

Here

http://www.batesville.k12.in.us/physics/phynet/Mechanics/Kinematics/BrakingDistData.html

is the first table I found on the net with braking decelerations.

Note that the 1995 BMW M3 was doing near-as-dammit a G, and would stop
from 60 in 37 metres. While the Dodge Colt would need 51 metres.

Obviously the Dodge driver, while travelling at his maximum safe speed,
would not be going as fast as the BMW could.

So the Dodge would hold up the BMW, even when travelling at _his_
maximum safe speed.

Have you never been stuck behind a lorry?

Andy