The use of drafting techniques is very common in
several sports involving moving objects at relatively
high speeds, such as cycling, motor racing
or speed skating [1–4]. The slipstream created
by the leading vehicle in a paceline reduces the
wind resistance of its followers. This can be used
to decrease the average energy expenditure of the
formation, such as in cycling, where the cyclists
ride in line or in a packed group known as a
peloton, but also to execute overtaking and bump
drafting manoeuvres, commonly seen in car racing.
As a moving vehicle approaches the vehicle
ahead, it enters a low pressure region (partial
vacuum), or slipstream, increasing its speed. This
additional velocity is often seized to carry out an
overtake. However, it is also sometimes used to
push the car ahead to higher speeds, acquiring a
cooperative advantage against the remaining competitors.
The technique is known as bump drafting.
Bump drafting became very popular in
NASCAR (the National Association for Stock CarAuto Racing in the USA), mainly at the Talladega
Superspeedway and Daytona International
Speedway race tracks, where racing cars can
easily reach top speeds and aerodynamic effects
become even more important. Indeed, if properly
used, this technique can be so efficient that cars
may gain a few seconds advantage per lap. This is
a significant competitive advantage in sports that
are often resolved by tenths of a second. Owing
to the shape and aerodynamic design of the cars,
bump drafting is not so common in open-wheel
racing cars, such as in Formula One. However, in
the penultimate weekend of the 2012 GP3 Series
season, a then 21 year-old racing driver, António
Félix da Costa, bump drafted the car in front of
him over the long straight of the Monza Circuit
in Italy, closing the gap between the two and the
race leader. The feat was so unexpected that it
caught the attention of several people outside the
sport. In the words of the live broadcaster, Will
Buxton, ‘look at him on the back of Aaro Vainio...
that’s bump drafting if ever I saw it. This is like