Answer:
Code in Javascript.
Preconditions:
All the variables are defined and initialized.
if (speed < 0) { // if speed is < 0 then adds 1 to reverse drivers.
reverseDrivers ++;
} else if (speed < 1) { // else if speed is < 1 then adds 1 to parked drivers.
parkedDrivers ++;
} else if (speed < 40) { // else if speed is < 40 then adds 1 to slow drivers.
slowDrivers ++;
} else if (speed <= 65) { // else if speed is <= 65 then adds 1 to safe drivers.
slowDrivers ++;
} else { // else if speed is > 65 then adds 1 to speeders.
speeders++;
}