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The history of race timing

The history of race timing

August 15, 2024

The history of RFID for race timing

Many people ask how it is possible for thousands of runners to receive a unique time during a race.

The short answer is radio-frequency identification (RFID) technology, which uses electromagnetic fields to identify tags that are attached to objects.

At a race, the timing equipment creates an electromagnetic field, which identifies bib numbers at the start and finish lines. The equipment then sends data with time stamps of the bibs crossing through the magnetic field to software. The software aligns the time stamps with a participant’s registration information to produce race results.

RFID originated during World War II from technology created by the Soviet Union for a covert listening device and technology developed by the Allies to identify opposing aircraft.

In the late 1980s, RFID was first used to time a motor race. In the mid-1990s, a lower cost transponder (134 kHz transponder) was released by Texas Instruments, which allowed RFID to become more widely adopted by athletic events. Despite being less expensive, the production cost of the 134kHz transponder still required it to be returned to the event organizer following the race so that it could be reused.

In the early 2000s, a new transponder (ultra-high frequency) became available that was cheaper to produce in volume. The lower production cost meant that it now made economic sense for an athlete to dispose of the transponder following a race. Today, many of the world’s largest athletic events use ultra-high frequency transponders (aka timing chips) to time their races.

Timing equipment and bibs work similarly to how a credit card works with a tap to pay reader. The race timing equipment creates a magnetic field and the bib acts as a credit card that gets identified as it crosses through the magnetic field.

In addition to race timing , RFID technology is used in many other ways today including inventory management, commerce, animal identification, passports and more.

A special thanks to my partner, Tim Krueger, for explaining RFID timing in a way that I could understand and to Alan Jones for spending way more time than he needed to help me understand the software that he wrote to time races, RunScore.

— Ian