A regularity rally, also called time-speed-distance or TSD rally, is a type of motorsport rally with the object of driving each segment of a course in a specified time at a specified average speed. The rally is usually conducted on public roads, but sometimes includes off-road and track sections. Contestants usually compete in teams composed of an amateur driver and navigator. Teams usually start a regularity rally at fixed intervals, creating a field that is spread along the course.
Origins
Regularity rallying shares its origins with most types of rallying. Unlike the well-known 'special stage rallying' (which is commonly just called rallying), regularity rallying does not depend on the abilities of the driver at high-speed nor does it depend on the speed that the vehicle can achieve. For this reason, ordinary motor vehicles can be used. (Regularity rallies are commonly held for classic or even vintage cars, see below.) Regularity rallying, therefore, is a far less expensive sport and can be enjoyed by a far greater spectrum of people. With the commercialisation and increasing competitiveness of special stage rallying, many people have been financially excluded from the sport and have therefore created many cheaper alternatives. The closest motor sport to regularity rallying is road rallying. Unlike a road rally, a regularity rally focuses somewhat more on the maintenance of precise speeds and times rather than on navigation. Navigation does, however, still play an important role in regularity rallying.
Characteristics
A typical regularity rally may run for a few hours or it may run over a series of stages over a few days.
At the start, competitors are usually briefed about the event and may be required to submit their cars for inspection. Each team is given a route schedule prior to departure. This schedule contains information that the navigator will use to try to keep to the specified route and it contains information about the designated speeds and times for each segment of the route. On some rallies, more than one type of schedule may be prepared for different types of competitors.
Once a team is prepared, they will usually start the rally at a specific time unique to them. Along the route, the team will encounter marshals. The position of the marshals is usually not known to the teams. The time at which the team arrives at each marshal is recorded and used in the scoring. In some cases the marshals are hidden from view. Teams may also encounter open sections where they are guaranteed not to encounter marshals and are not subject to any time penalties. There may be various other features along the route including points at which teams must wait for an 'exact time of departure', points at which teams must record their own times, etc.
Every regularity rally should have a deterministic route schedule. This means that the organisers can work out the exact times that should be recorded for each team at all the relevant points along the route. The difference between a team's actual times and the correct times determine their penalties. (Lateness and earliness both attract penalties.) The team with the lowest number of penalties wins.
Equipment
It is usually possible to compete in a regularity rally using only a car (or sometimes a motorcycle) and a stopwatch, but many regularity rallyists use various devices in an attempt to reduce their total penalties. The rules of each rally determine which devices are permitted. Some common aids include:
Odometer: Odometers can range from the odometer included on the dashboard of most cars to specially manufactured rally odometers. Speedometer: As with odometers, speedometers used by rallyists range from those built into the vehicle to specially manufactured rally speedometers. Stopwatch: Accurate time is essential in regularity rallying. GPS: GPS units provide speed, distance and navigational data, but there is some debate as to their usefulness in regularity rallying. Computer: Computers ranging from custom-made units to laptops can be used in some regularity rallies. Smartphone: Modern day smartphones and tablets allow the installation of apps that provide similar functionality to the previously mentioned devices. Curta: This mechanical calculator was popular among contestants in rallies during the 1960s, 1970s and into the 1980s. It was affectionately known as the "pepper grinder" or "peppermill."