Wired has an article that demonstrates why Indy races are–or at least were–lame. The drivers considered it too dangerous to race side-by-side. It is dangerous. If you want to drive safely please visit the public highways. We could always use more safe drivers out there.
Things are beginning to improve. Indy racers now have a power-up button. It is a nifty trick based on telling the engine to stop wasting power on the alternator for a few seconds. The system still needs work, however. Rather than awarding a set number of these power-ups based on timing alone, they need to activate this ability based on a driver passing over a specific part of the track. There needs to also be a chance to acquire the ability to selectively target and slow down another driver. And an electromagnetic accelerator that just takes a car that passes into it and accelerates it another 100 mph or so. And missiles would be cool, tool.