Transit 101: Relief Points
Recall that after we write the bus schedule we need to divide the schedule up into runs for the individual drivers to work . Since the bus driver is usually not working the entire time the bus he is driving is out on the road, he or she needs to meet the bus at a particular place. In the case of a pull relief, where the new driver takes a fresh bus out of the garage, he or she is already in the correct location. All other shifts involve the new driver taking over from the previous driver at a relief point.
All relief points have one thing in common: they are a time point on a particular route. Otherwise the driver's schedule could not be created because the bus would pass by the relief point at an uncertain time.
In addition, because buses may be delayed at the relief point for a few minutes due to the driver change, relief points need to meet many of the same requirements as layover locations .
Beyond the above, many union contracts stipulate that relief points must occur at the closest point a particular route passes to the garage. In the case of street reliefs, this means that drivers do not have to walk or take the bus very far, and in the case of what Hastus calls "taxi" reliefs - shift changes that involve drivers driving a company car from the garage to the relief point - the amount of time spent driving is minimized.
In some cases, relief points can change depending on the time of day and day of the week. For example, if connecting buses do not operate very often on the weekend then the normal relief point could be changed to something that is easier to access on transit. Driver safety could mean that some relief points are not used at night; in fact, many transit properties stipulate that driver reliefs cannot take place after a certain time. In practice, this means that all night runs are straight runs.
Due to the time it takes for the new driver to set themselves up in the seat - adjusting the mirrors, logging into the farebox, punching transfers, etc. - it is better, from the passenger perspective, that driver reliefs take place at the route termini. Switching drivers at the end of the route means that the layover time can be used for set up, avoiding passenger delays that happen during mid-route driver changes.
As shift changes can only happen at relief points, they can have a large effect on the finances of the transit system. For example, it would not be uncommon for a really long route - one that takes approximately two hours to complete a round trip - to have only one relief point. Such a route would likely either have a lot of guarantee time (where drivers get paid for eight hours even if they work less) or overtime, as it is difficult to cut a schedule into neat eight hour runs when you only have one opportunity every two hours to change the driver.
Of course, pull reliefs avoid many of the problems discussed above, especially by eliminating passenger delay attributable to driver change and problems of accessing the relief point from the garage. Problem avoidance is precisely why some transit agencies continue to use pull reliefs despite the fact that they cause two major problems of their own - by virtue of the additional non-revenue time they add they are more costly than other types of reliefs and they require the property to have additional buses. The additional non-revenue time contained in the time it takes to drive the bus from the garage to the start of the route is really only a problem if the agency engages in street reliefs - where the driver is only paid once he arrives at the relief point - and not in taxi reliefs, where the driver, like in pull reliefs, begins to get paid at the garage. The main problem, which is apparent to anybody who has ever seen two buses with "Not In Service" signs passing each other, is the increase in vehicle requirements. Unless there is time for the first driver to take the bus back to the garage for the second driver to use, there will be overlapping buses.