Additional Performance Measures
OKI continues to incorporate several additional congestion management performance measures within the CMP to further assess congestion and identify areas for transportation improvement. These additional performance measures are:
Travel Speed & Travel Speed Index
Roadway Level of Service
(LOS)
Travel Time Index
(TTI)
Intersection Delay and Level-of-Service
(LOS)
Peak Period Travel Times between Major Destinations
Incident Clearance Time
Transit Ridership
Travel Speed
Travel speed is a typical measure of performance for a roadway segment. The level of service (LOS) for a roadway or highway segment is determined using average-speed data. Both NPMRDS and INRIX data were used to determine travel speed during morning (6-10 a.m.), midday (10 a.m.-4 p.m.), evening (4-8 p.m.), overnight (8 p.m.-6 a.m.), and all day time periods.
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Travel Speed Index
Travel speed index (or speed index) is a ratio that is calculated by dividing a roadway segment’s average travel speed by the posted speed limit for that roadway segment. For example, if the speed limit is 50 miles per hour and the average observed travel speed is 40 miles per hour, the speed index is 0.80.
The OKI Speed Map shows average speed and daily travel speed index by roadway segment during a.m., midday, p.m., all hours, and overnight time periods in 2024.
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Roadway Level of Service
Roadway level of service (LOS) is based on the daily traffic volume on roadway segments. The approaches provided by FHWA guidance were used to estimate the LOS. The volume range for each LOS A through F depends on the facility type, number of lanes, area type, speed limit, and truck percentage. LOS A and B provides a traveler with the best travel with little to no friction with other vehicles. LOS C indicates more traffic volume with a small decline in mobility. Each letter grade after indicates worse roadway traffic conditions, with LOS F indicating gridlock and very low traffic speeds. The map shows the roadway level of service in 2020.
Travel Time Index (TTI)
The relative severity of travel congestion is measured by the ratio of the peak travel time to the travel time at free-flow speeds. A travel time index of 1.2 means travel speeds are 20 percent slower than free flow for a given time period. Travel time index measures how much congestion is present for a given road segment. The map shows several contiguous bottlenecks occurring during the morning (6-9 a.m.) and evening (4-7 p.m.) weekday peak periods in 2024.
Congestion can also occur outside of peak hours and can vary in intensity within the hour. The duration relates to the amount of time congested conditions persist before returning to an uncongested state. The chart presents the four roadway segments in the OKI region to experience 12 hours of congestion or more per day.
Intersection Delay and Level-of-Service
Intersection delay is the average time needed for a vehicle to pass through the intersection. The average time is reported in seconds and is the cumulative delay of all vehicles. Each intersection is assigned a level-of-service based on the delay.
Data was collected on typical summer and fall weekdays in 2019, 2021, 2022, and 2025 from 7-9 a.m. (AM Peak) and from 4-6 p.m. (PM Peak) at regionally significant intersections to assess both intersection delay and level of service. The results of the intersection capacity analysis are shown in the map.
Peak Period Travel Times between Major Destinations
To examine travel times within the OKI region, major destinations, including the Greater Cincinnati/Northern Kentucky International Airport (CVG), downtown Cincinnati, Eastgate shopping area, Northern Kentucky University, Xavier University, University of Cincinnati, Kings Island and Sharonville, were chosen for analysis.
PM peak travel times were used because PM is typically more congested. The travel times are average weekday PM peak hour travel times for 2021 and 2024. Times are for a route on the shortest interstate highway path between destinations. These times only include travel to the section ending nearest the destination; therefore, a small amount of additional travel time, not reflected here, may be necessary to reach the destination.
Incident Clearance Time
ODOT’s Ohio Traffic Incident Management (OTIM), is the state’s traffic incident management program comprised of ODOT, local and state law enforcement agencies, Fire Department, EMA, and towing and recovery services. Traffic incident management is the process of coordinating resources to detect, respond to, and clear traffic incidents as safely and quickly as possible to reduce the impacts of crashes and congestion.
Incident management consists of a planned and coordinated multi-disciplinary process to detect, respond to, and clear traffic incidents so that traffic flow may be restored as safely and quickly as possible. Effective incident management dramatically reduces the duration and impacts of traffic incidents. The ODOT Traffic Operations Control Center in Columbus monitors traffic with over 80 cameras in the OKI region and facilitates communication among law enforcement and emergency responders.
The chart shows the trend in average clearance time by quarter. Clearance time refers to the duration between when the incident record was opened and closed.
Transit Ridership
Nearly all transit trips occur on the Congestion Management Network; therefore, highway congestion directly impacts transit travel. Increasing transit ridership helps reduce demand on the highway system. The OKI travel demand model estimates that public transportation eliminates less than 10,000 daily person trips by automobile. The chart shows trends in annual ridership by transit agency.