Open IIS Manager and navigate to the level you want to manage. For information about opening IIS Manager, see Open IIS Manager (IIS 7). For information about navigating to locations in the UI, see Navigation in IIS Manager (IIS 7). In Features View, double-click Authorization Rules. In the Actions pane, click Add Allow Rule.
Many tractors have mechanical brakes, operated by a linkage and cam system instead of a master/slave fluid system. These brakes are located on the rear axles, and work independently, so that they may be used to steer the tractor in tight corners or to reverse the direction of travel. The brake pedals will interlock for road travel, so that one pedal is not accidentally engaged by itself, causing the tractor to spin while traveling at a high speed.
Federal Motor Vehicle Safety Standard No. 121 mandates antilock braking systems (ABS) on all new air-braked vehicles with a GVWR of 10,000 pounds or greater. ABS is required on tractors manufactured on or after March 1, 1997, and air-braked semi-trailers and single-unit trucks manufactured on or after March 1, 1998. Crash data from NHTSA's State Data System and Fatality Analysis Reporting System are used to determine the effectiveness of antilock brakes in heavy tractor-trailer combination vehicles.