Traffic Volumes

Traffic volumes are measured in terms of daily and peak hour. Daily traffic volume measurements include a total twenty-four hour volume, while peak hour volumes include only a one-hour period (typically the morning and evening “rush hour”). Each measurement has different uses. Clicking on a segment of the existing traffic conditions map displays the volume information for that roadway segment.

Existing Traffic Conditions

Currently I-25 is operating at an acceptable level of service within most segments. However, future traffic growth must be considered while evaluating improvements. As traffic grows, the levels of service will worsen.

US 85 is currently operating at unsatisfactory levels of service. The poor traffic operations on US 85 warrant improvements under the existing volumes. Traffic volumes will continue to increase and without improvements, operations will continue to deteriorate.

Click the Segment Number links on the map to view the Annual Average Daily Traffic (AADT), Peak Hour Volumes, and the resulting Level of Service (LOS) rating for each of the segments of I-25 and US 85 within the EIS Corridor.

For detailed information regarding the LOS rating system: Level of Service

• Annual Average Daily Traffic

The annual average daily traffic (AADT) is the volume of traffic traveling on a roadway on a typical (or average) day of the year. The traffic volume can be displayed by travel direction or both directions combined.

As shown on the figure, traffic volumes increase on I-25 and US 85 as the traffic travels north towards Denver. The average number of vehicles driving on I-25 in one day between Plum Creek Parkway and Wolfensberger Road is 60,250 while 77,500 vehicles drive on the segment between Schweiger and Lincoln Avenue. The average number of vehicles driving on US 85 in one day between Meadows Parkway and Happy Canyon Road is 13,200 whereas 37,600 vehicles drive on the segment between Town Center Drive and Blakeland Drive.

• Peak Hour Traffic Volumes

Peak hour volumes occur during the hours experiencing the largest volumes of traffic on a given roadway segment. Peak hour volumes are determined for the AM and PM (“rush”) hours. The peak hour typically occurs between 6:00 a.m. and 8:00 a.m. and 3:00 p.m. and 6:00 p.m. on I-25, while the peaks on US 85 occur between 8:00 a.m. and 10:00 a.m. and 4:00 p.m. and 6:00 p.m. Peak hours represent the worst case traffic conditions and is used in the design of a roadway in terms of required laneage (capacity).

• Traffic Variation

Both daily and peak hour traffic volumes vary by time of day in terms of volume and travel direction as shown on the following graph.

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