Indy 500 - On the Wire (1915)

From the January 1915 issue of Popular Mechanics, a view of the wire suspension bridge that spanned the 80 foot width of the track from the pagoda to the grandstands at the start/finish line. The three-foot wide bridge was used by the flagmen and race officials during the race, an improvement from having the flagman step out onto the track itself to signal the drivers.