Racing drivers and sports fans alike have been warned to watch their speed or get caught by extra camera traps put in place for the Wales Rally GB.
Organisers are hoping to sell more than 120,000 tickets
Police are out in force with extra traffic controls on key roads used to get to various stages of the competition, following considerable problems with speeding motorists during last year's event.
During the 2002 competition, hundreds of motorists were sent speeding fines after being allegedly caught by mobile speed cameras.
Organisers have promised an increased emphasis on spectator safety for the 2003 event. Around 3,000 volunteer marshals will police the 18 stages, which started in Cardiff on Thursday and ends at Margam Park, Port Talbot, on 9 November.
The main focus will be Swansea Rally Centre at Felindre although stages will be held throughout the region.
Despite some public aversion to speed cameras, South Wales Police have said they make no apology for putting additional ones in place.
"Despite advanced warnings via the local press and media, we were disappointed by the high incidences of speeding offences during the 2002 event with speeds of up to 135mph being driven between stages," said Superintendent John Rowling, head of the South Wales Safety Camera Partnership - a UK Government-backed initiative.
"As a result, we have been working closely with rally organisers to put controls in place to reduce the number of motorists speeding and we will be stepping up enforcement with mobile speed camera units and traffic policing.
" We are seeking prevention rather than cure. We do not operate a policy of catching people out and, for this reason, we are surrounding this enforcement with advanced warning and high publicity."
Organisers are hoping to top the 120,000 ticket sales of last year which saw spectators coming from as far away as North America.
The rally attracted 38.5m spectators, who watched stages on the television and the internet.