ASPHALTopics | Spring 2014 | VOL 27 | NO 1

New Indy road course
a winning formula
by Lisa Fattori
IMS photo(s) by Chris Owens.
Racing enthusiasts can look forward to a newly
paved and modified road course at the world
famous Indianapolis Motor Speedway (IMS) this
season. The upgraded 2.439 mile infield circuit will host
the inaugural IndyCar Indianapolis Grand Prix May 8th
to 10th, as well as MotoGP’s Red Bull Indianapolis GP in
August. The improvements not only ensure the safety of
the course, they make the race more thrilling for drivers and
spectators alike.
“The original course was constructed in 1999, and some
severe cracking had taken place,” says Kevin Forbes,
IMS Director of Engineering. “Unlike highways that have
a constant kneading action, raceways don’t have the
steady traffic and will crack as a result. The geometry
of the course also needed to be changed. Some of the
corners were changed to make the race more competitive
for drivers and therefore more entertaining for spectators.”
Construction of the road course began in September 2013
and was completed in just two months. The scope of work
included milling the existing pavement, with the removal
of five inches of asphalt, and the installation of five inches
of new pavement. Corners one and two of the road course
were completely changed to offer a slight elevation of
approximately three feet. The corners were excavated
down 14 inches and received a seven inch base of crushed
stone, followed by seven inches of new asphalt. The
sections were then married to the existing portions
of the road course that remained in place.
“At first we were going to remove the pavement all at
once, but the base would be damaged from trucks and
machinery,” Forbes says. “Instead, we re-paved the course
in sections, leaving just enough asphalt to work from.”
The elevation changes make for a more varied course and,
although three feet may not seem significant, the change
will enhance competition. “The speedway was built on
Indiana farmland, which is completely flat,” Forbes says.
“The interior road course is already surrounded by a lot
of infrastructure, so it is difficult to find opportunities
where we can create a hump or hill. Three feet is pretty
significant and will make the road course more interesting
and fun for race car drivers.”
Turn 12 of the road course intersects with the warm-up
area of the oval track, which is also the fourth turn of the
MotoGP circuit. To make the geometry of the road course
even more interesting, it is designed to accommodate
IndyCar Series races moving in a clockwise direction,
as well as MotoGP races that run counter clockwise.
The 100 square feet shared space is an engineering feat,
successfully accommodating four paths that cross in the
same location. All pathways have different geometry, both
horizontal and vertical, with certain banking required for
each. The design had 900 data points and demanded
unconventional paving practices to get the desired finish.
“Screed operators tend to think just of drainage, but
this section required the screed to go in four different ››
12 OHMPA | ASPHALTOPICS