For a signalized intersection with a posted speed limit of 40 mph, what is the minimum total change period using the "ITE procedure" for a cross street width of 70 feet?

The minimum total change period at a signalized intersection is essential for ensuring the safety of both vehicles and pedestrians during the transition from a green to a red phase. The ITE (Institute of Transportation Engineers) procedure provides a method to calculate this period based on factors such as posted speed limit and cross street width.

For a posted speed limit of 40 mph and a cross street width of 70 feet, the ITE procedure typically uses a combination of vehicle perception-reaction times and the time needed for vehicles to clear the intersection.

The calculation involves determining the time it takes for a vehicle traveling at that speed to cover the width of the intersection. Considering that a vehicle at 40 mph travels approximately 58.67 feet per second, the time it takes to cover a 70-foot cross street can be calculated. Factoring in a typical perception-reaction time, which can add to the total time needed for an effective change period, results in a minimum total change period.

When performing these calculations, the ITE procedure suggests a minimum total change period of around 5.5 seconds, which encompasses both the clearance interval for vehicles and the yellow light interval needed for safe stopping distance. This ensures that all drivers can react and either clear the intersection