From my experience in the Metro Indianapolis/Marion County area listening to ISP,Speedway Police and Fire along with IMPD. Last years race in 2010 I heard most of the Radio Traffic on Safe-t on ISP TALKGROUPS 52-OPS1 and 52 -OPS2.Also Speedway Police and Fire will be on their talkgroups along with IMPD will be on one of the many S1 talkgroups away from the regular IMPD Talkgroups.Safe-t talkgroup 6416 will be very active for traffic for Hoosier Helpers helping people who break down on the interstates.Also a GMRS Repeater will also be active here in the Metro Indianapolis/Marion County area---462.675 for radio communications relating to the race weekends up to raceday.On raceday,Radio Traffic will include road patrols, weather infomation, and traffic infomation relating to The Coke lot and other lots as far as how much they are filled up with.I would recomend that you listen to Safe-t. MECA Talkgroups provided, along with GMRS Repeater 462.675. Also VHF-Air Speedway tower which controls all of the airspace over the speedway will be on 118.675.If the Goodyear Blimp is in town providing coverage from the air they will be on 151.625.Also Newsmedia(ABC) will be on 450Mhz along with The IMS Indianapolis Speedway Radio Network.I live 10 Miles to the Northwest of the Track in Speedway and I hear what is going on before raceday and also on raceday from start to finish.