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." Roadbook or roadmap The roadbook or logbook is a type of map encoded with the correct road to be followed. It counts for all the information about the distances, time and average speed that must be followed throughout the race. It is through these sheets that the navigator will direct, as well as pace, the driver. At the rally the book is divided into several sections that may be of the following types: Regularity Tracks: are the passages in which the contestants must maintain a predetermined average speed, expressed in km/h. Averages are compatible