Safety Evaluation of Signalized Restricted Crossing U-Turn Intersections

Chapter 6. Economic Analysis

This evaluation included an economic analysis on the installation of a signalized RCUT. The results of this analysis can help inform transportation agencies on the benefits and costs of this countermeasure.

To conduct the analysis, the project team employed annualized benefits and costs. Benefits included fewer crashes and shorter travel times. The costs included construction of the RCUT and maintenance of the extra traffic signals required by the RCUT. These benefits and costs should entail the majority of all quantifiable impacts of RCUT installation. The analysis essentially estimated the effects of signalized RCUT installation at a site that has characteristics that are average compared to the 11 test sites in this research.

The project team obtained construction cost data for 9 of the 11 test sites, as shown in table 15. Officials in Alabama emphasized that cost estimates were for RCUT-related items only, while officials in Ohio stated that cost estimates included items that were indirectly related to the RCUT. In that regard, underestimates from Alabama might balance overestimates from Ohio and still provide what looks to be a reasonable average.

AL = Alabama; OH = Ohio; TX = Texas.

The following assumptions were made during the analysis:

• All benefits and costs were in 2014 dollars.
• Inflation was not relevant to bring the construction costs in table 15 to 2014 dollars or to annualize other benefits and costs into the future.
• RCUTs have a 20-year useful life, like other intersection improvements.⁽⁷⁾
• There is a 7-percent-per-year discount rate.
• On average, the RCUT major street carries 52,000 vehicles per day.
• On average, the RCUT minor street carries 10,000 vehicles per day.
• There is no traffic growth during the analysis period.
• Thirty percent of daily traffic occurs during the 4 peak hours of the day.
• The RCUT saves 20 seconds per vehicle during the 4 peak hours of the day and has no net operational effect at other times of the day, in line with previous estimates of the effects signalized RCUTs.⁽¹⁾
• Time savings are valued at $15 per hour, in line with typical economic analyses.
• There are 250 working days per year that experience time savings.
• Each extra traffic signal costs $5,000 per year to maintain and provide electricity.⁽⁸⁾
• Without the RCUT, crashes would have occurred at the same annual frequency as in the before period at the 11 test sites during the whole analysis period.
• The property-damage-only CMF was 0.85, equivalent to the total CMF in table 11.
• The injury and fatal CMF was 0.78, per table 14.
• The property-damage-only crash cost in 2014 was $18,000.^(9,10)
• The injury and fatal crash cost in 2014 was $384,000.^(9,10)

The analysis resulted in a $354,000 annualized construction cost. When added to the annual maintenance cost for three extra signals at $15,000, this yielded a total annualized RCUT cost of $369,000. For benefits, using several of the assumptions above, the project team estimated the operations to save 103 hours of motorist time per workday, which equates to $388,000 per year. The safety benefit was a savings of 3.0 property-damage-only crashes per year and 2.3 injury and fatal crashes per year, which results in an annual monetary savings of $948,000. Thus, the B/C ratio was 2.6 to 1.0 considering the safety benefits only and 3.6 to 1.0 considering the safety and operational benefits.

The U.S. Department of Transportation (USDOT) recommends testing the sensitivity of economic analysis results to differences in crash costs by examining the results with 0.57 and 1.41 times the recommended crash costs.⁽¹⁰⁾ Table 16 provides the results from that test. Even at the low levels of crash cost, considering safety only, installing a signalized RCUT at sites like those tested under the assumptions previously listed will be beneficial, and at high crash cost levels, the effort is very beneficial.