The fastest road race in the world is the Silver State Classic Challenge held on Nevada's Route 318, in which the fastest cars can surpass speeds of 394 km/h (245 mph) over the 145-km (90-mile) course. The highest ever average speed in the race was 353.4811 km/h (219.6430 mph), by Robert Allyn (driver, USA) and David Bauer (navigator, USA) in a 2001 Monte Carlo NASCAR during the 2017 Nevada Open Road Challenge, on 21 May 2017.Highly organized, with the full endorsement of local law enforcement, the race was first run in 1988, and is now held biannually in May and September. The very high speeds in the race are made possible by the nature of the highway: it is largely straight and flat, with a series of technical corners posted at 72 km/h (45 mph) in an area called the “narrows”. More than 200 amateur drivers from all over the world converge on the small town of Ely, Nevada (www.elynevada.net) the starting point of the race. While there is an "unlimited" class which is won by the highest average speed, the majority of the classes at the event are about drivers coming closest to a pre-declared average speed. Governed by strict rules, vehicles are required to be driven by internal combustion engines running pump fuel. The addition of octane performance boosters is permitted, and turbochargers and superchargers are also allowed. However, the car must be "closed wheel and have the appearance of a production automobile or truck".