FM 7-22, Appendix A, A-3 Test Site.
A-17. Sound judgment must be used in the selection of a 2-mile run course. There is no requirement to survey 2-mile run courses; however, selected test sites should be free of significant hazards such as traffic, slippery road surfaces, and areas where heavy pollution is present. Running tracks may be used to administer the 2-mile run event. If a 400-meter track is used, the OIC/NCOIC must add an additional 61 feet, 4 inches to the standard 8 laps to ensure the test’s required 2-mile distance is covered. One lap on a 400-meter track is 92 inches shorter than one lap on a 440-yard track. Eight laps on a 400-meter track is 736 inches shorter than eight laps (2 miles) on a 440-yard tack. Therefore, Soldiers running on a 400-meter track must run an additional 61 feet, 4 inches.
As to the question about width. You would have to specify your situation. Yes I understand on a track that there is a big difference in a standard lap distance from inner lane to outer lane, but nothing forces you to run the outer laner so the width isssue is not considered a detriment to the runner.