This article is from the Formula One Motor Racing FAQ, by email@example.com (Mitchell McCann) with numerous contributions by others.
Cars must not exceed the pit lane speed limit, which is
different at each track. As driver comes in, one of the pit crew
indicates the location of the pit (it isn't easy to find in the
heat of the moment). The car stops on the marks and is lifted by
front and back jacks. Three mechanics are required for each
wheel; one to operate the tool to remove/replace the wheel, one
to take the old wheel off and one to put the new one on. In
addition, two are required to handle the fuel hose, and a couple
of spares wipe the drivers' visor etc. The operation is
controlled by the chap at the front who holds the 'brakes on'
sign, and he looks out for all the mechanics to raise their
hands as a signal that they are finished and out of the way.
Then he signals for the car to be dropped off the jacks and the
driver can leave. Due to the restrictions on the equipment,
re-fueling actually takes longer than the tyre change.
Crews rehearse before every Grand Prix to keep in practice. As
there is now fuel being thrown around in the pitlane, all
mechanics wear fireproof overalls, and sometimes helmets too. A
few near-disasters have stressed that the pit lane is a
dangerous place, and personnel there should be kept to a
minimum.(i.e. groupies, relatives, under-age royals etc should
be somewhere else!) The driver should keep his visor closed
during a pit stop in case of fire. IMHO there WILL be a
disastrous fire unless refuelling is banned.