on the setup button to set up the cars. Click on go
to start the cars moving and the swans swimming.
number slider controls the number of cars on the road.
(If you reset the number of cars, you will need to stop-it
and then click setup for the changes to take effect.)
lookahead slider controls the distance that drivers
look ahead (in deciding whether to slow down). The speedup
slider controls the rate at which cars accelerate when
there are no cars ahead. The slowdown slider controls
the rate at which cars decelerate when there is a car