Peak Hour vs. Peak Period

Most of the analysis conducted by MRMPO has focused on the peak “one hour” of travel, the standard for traffic analysis. However, when travel demand is analyzed over the common industry standard of just one hour, we might be missing an opportunity to assess the network’s capability to offer additional capacity over a longer timeframe, such as a “three-hour” peak period. 

MRMPO has begun to explore the travel conditions associated with peak period travel for the longer three-hour peak periods. What we can see from the data is a more precise evaluation of when the roadway is above, below, or approaching capacity within this interval of time. This type of analysis reflects the phenomenon called “peak hour spreading.” 

Peak Hour Spreading

The graphic above depicts this phenomenon. In this example, we can see that there is an opportunity to take advantage of additional roadway capacity that is available during this three-hour peak period to help avoid having to physically expand the roadway. As travel demand continues to increase, focusing on the “peak hour” will be inadequate, requiring MRMPO to analyze additional capacity using the entire three-hour peak period. Often, and on certain corridors where it is advantageous, these “tails” of the three-hour peak period contain a significant degree of cost-effective additional capacity. If travel patterns can be shifted or offset sometimes by as little as 15 minutes to ½ hour, additional capacity – without having to expand the roadway – can be easily achieved. 

Stay tuned for more interactive links (under construction).