[Alan Roehrich]

Any media used for a speed trap has to be constantly stirred and groomed, or it settles and compacts. Let it sit, get rained on, or generally weathered, and it will get relatively slick and hard. Vibrations from cars on the track, and trucks on that road only help that process (speaking of E-town). It also needs to have a pretty serious uphill grade, as much as you can put on it without cars digging in and going end over end (Force did that a few years back). Pea gravel, or creek gravel may work better than sand. They use it at some circle tracks and road courses, as well as in runaway truck ramps on highways. But you have to be careful how you stop the cars, and how fast you stop them.

Although it will really screw up the guys who like to coast, if they'd put an uphill grade on the shut down right after you pass the finish line, increasing as it goes, it may help slow the cars down.

The net issue is a harder problem to solve, since you have to stop the cars without stopping them so fast the driver can't survive, and without tearing the car apart. That's going to be really difficult and expensive, and given the difference between the widely varying cars, it may be nearly impossible, at least with just one net system. Different speeds, weights, and car structures will make it hard to make a net that stops all of them without destroying some of them. At least to NHRA, changing nets when you change classes could get cost and time prohibitive.