In addition, former Indy 500 drivers Fred Agabashian, Len Sutton, Johnny Rutherford, and numerous others have served as analysts.

In the years after World War II, Mutual utilized the services of WIBC to produce the broadcast and provide additional talent.

That year's race was cut short by rain, forcing Mutual to interrupt Queen for a Day to broadcast the finish of the rain-shortened event.

[12] For 1951, Mutual substantially raised its advertising rates,[4] and its primary sponsor, Perfect Circle Piston Rings, pulled its support.

[13] In early May of 1951, Speedway president Wilbur Shaw consummated a last-minute deal for WIBC to cover the race,[6] with Sid Collins as anchor.

[6] After the success of WIBC's radio effort in 1951, the Speedway management became interested in taking the broadcasting duties in-house permanently.

[6] During this time, the broadcast was typically simulcast on all of the major stations in Indianapolis,[14] and the nationwide affiliate count continued to grow rapidly.

Worldwide shortwave transmission through Armed Forces Radio started in 1953,[6] and claimed to reach every country where English was spoken.

[16] During his tenure as chief announcer, Sid Collins frequently referred to the outfit as the "Indianapolis Motor Speedway Network", omitting the word "Radio".

After the race went to live coverage on ABC-TV in 1986, then to NBC in 2019, the number of radio affiliates for the network steadily declined over the next two decades.

Prior to that, a radio booth was situated inside or in front of the wooden pagoda that pre-dated the Master Control Tower.

The three-man pit reporting crew of Chuck Marlowe, (north), Luke Walton (center), and Lou Palmer (south) became a fixture of the broadcast for over twenty years.

The faster pace of the broadcasts, as well as the fact that the chief announcer in the pagoda had a clear view of the entire turn, was the reason for the change.

The broadcast traditionally opens and closes with a rendition of the song called "The 500", originally recorded by the Singing Hoosiers and Jazz Ensemble of Indiana University, (lyrics written by Joe Jordan).

Due to the increased number of affiliates at the time, the network needed a scripted "out-cue" to alert radio station engineers and producers when to manually insert local commercials.

A young WIBC marketing staff member named Alice Greene (née Bunger) is credited with inventing the phrase, and chief announcer Sid Collins coined it on-air.

For the opening quarter-century of the Network's official independent existence, from 1952 to 1976, Collins served as the chief announcer, and ultimately as the template for all who have successively followed.

[6] After a fiery crash on the main stretch, Collins delivered an impromptu eulogy for Eddie Sachs, who was killed in the accident along with Dave MacDonald.

[29] There has been no consensus ever reached, and Page, Palmer, Jenkins, King, and Jaynes, all have been referred to over the years as either "Voice" or "Chief Announcer" whether formally or informally.

The radio network crew typically facilitated its own team of unofficial serial scorers to follow the progress of the race.

Rice performed "double duty", working the pits for the Indy 500, then flying to Charlotte Motor Speedway to call the Coca-Cola 600 later in the evening.

Rather, when incidents occurred on the track, the information would be relayed on cue cards to Collins, and the reporters would be called upon to summarize the details of what had happened.

[6] Booth interviews with celebrities, politicians, advertisers, promoters, retired drivers, and other famous personalities in attendance were used to fill the downtime of the broadcast.

Starting in 1971, Collins made an effort to curtail booth interviews, in order to improve the flow of the race, and to assuage listeners' complaints.

[6] When Paul Page entered the booth in 1977, he swiftly changed the face of the network, and in his own words, "brought the broadcast into the present tense.

[21] He "locked the doors" of the broadcast booth,[37] effectively eliminating the mundane celebrity interviews, and gave the turn reporters a higher level of play-by-play responsibility.

By the mid-1980s, the radio booth was equipped with a television monitor which could pick up the ABC-TV raw satellite feed, which gave the announcers access to replays for the first time.

Jenkins ditched the separate radio introductions, and for continuity purposes, began simulcasting the Speedway's public address system for the duration of the pre-race.

Jenkins enthusiastically served as chief announcer for nine years, but characterized the job as "complex"[6] as well as physically and mentally "exhausting.

Jenkins made a brief return to the radio crew as a turn reporter in 2007–2008, and as a booth analyst in 2009–2011, before permanently joining the Speedway public address announcing team until the end of 2019, when he was diagnosed with brain cancer that would lead to his death during the week of the NASCAR-INDYCAR doubleheader.