PMTravel is a combination of two programs which calculate travel times for
either miles or km. at different speeds.  The reason that I wrote these
programs is to show people how ridiculous it is to drive the 10 miles 
to work at 80 m/h when it only saves 1 minute, 43 seconds over
driving at the much safer speed of 65 m/h, and if you get pulled over for
speeding, how much time (and money) you'll spend for that 00:01:43.  Albiet,
driving fast for long periods of time can significantly reduce your driving
time, but I think that most people that I see are just driving around the city
on the freeways, and the time savings vs danger ratio is not worth it.