Travel Time Reliability: On-Time Arrival

Travel times vary greatly from day to day, and travelers remember those few bad days they suffered through unexpected delays. Travel time reliability measures the extent of this unexpected delay. On-time arrival provides an estimate of how many times a traveler is anticipated to arrive at the destination on time. Areas with the heaviest congestion on Florida's freeways are susceptible to unreliable travel times.

In 2019, on-time arrival along the freeways decreased from 2018 by 1.4 percentage points for the urbanized areas of the seven largest MPOs during peak period. Heavily congested facilities are susceptible to unreliable travel times, and the 0.4% decrease in daily reliability for the seven largest MPOs corresponds to the increase of 1,226 hours in daily hours heavily congested.

Methodology

Methodology: Travel Time Reliability: On-Time Arrival

For the urbanized areas of the 7 largest MPOs, on-time arrival is defined as the percentage of freeway trips traveling at least 45 mph. For all others, on-time arrival is defined as the percentage of freeway trips traveling at greater than or equal to 5 mph below the posted speed limit during the peak hour. For example, 80% on-time arrival indicates that the traveler is anticipated to arrive at the destination on time on 4 out of 5 trips.

Calculation

The on-time arrival for urbanized areas of the 7 largest MPOs was computed using the following equation:

`(Σ ("VMT at a Travel Speed" ≥ "45 mph"))/(Σ " VMT") ×100`

The on-time arrival for all other areas was computed using the following equation:

`(Σ ("VMT at a Travel Speed" ≥ "Speed Limit - 5 mph"))/(Σ " VMT") ×100`

Reporting Periods

  • Peak Hour
  • Peak Period
  • Daily
  • Yearly

Sources

FDOT - Traffic Characteristics Inventory
HERE Technologies - Travel Time Data