TSD rally
Also: Time Speed Distance rally, TSD
TSD stands for Time, Speed, Distance. It is a rally format where you must match time, average speed and distance exactly.
TSD stands for Time, Speed, Distance. A TSD rally is essentially the same thing as a regularity rally: you drive a set distance in a set time.
Where the term comes from
The term is common in the UK, North America and at international events. In German-speaking countries people tend to say Gleichmäßigkeitsrallye instead. If an entry form says "TSD", you know the event is about precision, not outright speed.
The three values
Time, speed and distance are linked. If you know two of them, you can work out the third:
- Time = distance ÷ speed
- 5 km at 30 km/h takes 10 minutes
- 5 km in 10 minutes means 30 km/h
While driving you keep comparing where you should be according to plan with where you actually are. For that you need an accurate odometer and a reliable clock. The average speed calculator does the maths for you.
Scoring
Times are taken at secret or published checkpoints. Depending on the regulations, penalties are given per second or per tenth of a second of deviation.