In a lane group with two lanes at a signalized intersection, what is the capacity if the adjusted saturation flow rate is 1,700 vehicles/hour/lane and the effective time is 30 seconds out of 80 seconds?

To determine the capacity of a lane group at a signalized intersection, you can use the formula:

Capacity = Adjusted Saturation Flow Rate × Effective Green Time

In this case, you have two lanes, an adjusted saturation flow rate of 1,700 vehicles/hour/lane, and an effective green time of 30 seconds during a total cycle time of 80 seconds.

First, calculate the effective green time in hours:

Effective green time = 30 seconds / 3600 seconds/hour = 0.00833 hours.

Now, since there are two lanes in the group, you calculate the total capacity as follows:

Total Capacity = Adjusted Saturation Flow Rate × Effective Green Time × Number of Lanes

Total Capacity = 1,700 vehicles/hour/lane × 0.00833 hours × 2 lanes

Total Capacity = 1,700 × 0.00833 × 2 = 28.33 vehicles

Next, to find the capacity in vehicles/hour, we compute:

Total Capacity = 1,700 × 0.375 (which is 30 seconds divided by 80 seconds)

Total Capacity = 1,275 vehicles/hour.

This calculation shows that the total capacity for the two-lane