Amount of Time

[Guest]

In the 1970's, a major city had the traffic signals spaced at a quarter mile. The cycle time (the time it takes to cycle through green, yellow, and red) at sixty seconds, vehicles traveling at 30 mph could reasonably 'expect to get a green.'

Please explain the calculations.

[Guest]

Please reply, Thanks.

[Guest]

Please respond. Thanks.

[Guest]

In the 1970s, it was common for major cities to space their traffic signals at a quarter-mile intervals. The cycle time, which refers to the time it takes for a traffic signal to complete one full cycle of green, yellow, and red lights, was typically set to sixty seconds. At that time, if vehicles were traveling at a speed of 30 miles per hour (mph), they could reasonably expect to encounter a green light at each traffic signal along their route.

The quarter-mile spacing of traffic signals was designed to provide a relatively smooth flow of traffic. By coordinating the signal timings, city planners aimed to optimize traffic progression, allowing vehicles to maintain a consistent speed without encountering excessive stops. The goal was to reduce congestion and enhance the efficiency of the transportation network.

With a cycle time of sixty seconds, signals were timed to ensure that a vehicle traveling at 30 mph would reach the next signal just as it transitioned to a green light. This synchronization allowed drivers to proceed through the intersection without having to stop at each signal, assuming they maintained a steady speed within the designated limit.

It's important to note that traffic signal timings and spacing can vary significantly between cities and even within different time periods. Modern traffic management systems employ advanced technologies and algorithms to dynamically adjust signal timings based on real-time traffic conditions, optimizing traffic flow and reducing delays.

[Guest]

Thanks.

Check my calculation, please.


Signals placed at quarter-mile intervals: .25

Timed at 60 sec. equals .016 hrs. (60 / 3600)

Traveling at 30 mph.

Rate * time = distance.

30 * .016 = 0.48


Where did I miscalculate ?

[Guest]

Your calculation is correct, but there is a slight error in the interpretation of the result. Let's break down your calculation step by step:

Signals placed at quarter-mile intervals: 0.25 miles
Timed at 60 seconds equals 0.016 hours (60 seconds divided by 3600 seconds to convert to hours).
Traveling at 30 mph.
Rate * time = distance.

30 mph * 0.016 hours = 0.48 miles

So your calculation is accurate, and the result is 0.48 miles, not 0.48 hours. It means that if you travel at a constant speed of 30 mph for 0.48 miles, you can reasonably expect to encounter a green light at the next intersection, assuming the traffic signal timing is synchronized with this spacing.

[Guest]

Ok, Thanks again.

[Guest]

Ok, Thanks again.