The opportunities to learn when present at an event like an American LeMans Series race are so much greater than from just reading about it! As you having been reading on CorvetteBlog, the ALMS just made its Michigan debut this past weekend. The ALMS portion of the Detroit Belle Isle Grand Prix was a two hour, 45 minute timed event.
The ALMS includes four classes of vehicles in each race:
LMP1 -- Purpose-built, closed wheel cars that are among the most technologically advanced and fastest sports cars in the world
LMP2 -- Slightly smaller, less powerful, yet extremely nimble vehicles, with proven capability of winning overall
GT1 -- Heavily modified versions of production cars; this class includes the Corvette C6.R
GT2 -- Production sports cars with few modifications
Because of the additional complexity that comes from having four classes of vehicles competing at the same time, an exclusive innovation assists race watchers to keep track of the leaders: the Leader Light System.
Three leader lights are located on the sides of each race car. One light is lit for the leader in his class. Two lights indicate second place. Three lights indicates third place. No lights indicate that the car is not in the top three.
This close-up shows the Number Three Corvette in the pits. Note the three unlit lights just to the ight of the U.S. flag, and below the "E" in Compuware:
The color of the light also has meaning, as each class has a unique color
LMP1 -- Red
LMP2 -- Blue
GT2 -- Yellow