Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Appendices
A study conducted by the Texas Transportation Institute (TTI) on bottleneck removal showed that all sites experienced a safety
benefit increase ranging from 5 to 76% with an overall average of approximately 35% (51).
• Mobility: Bottleneck removals on US-59, Houston, I-40 and I-25, Albuquerque, I-25 and I-225, Denver resulted in an estimated
total delay reduction of 19.2, 14.9 and 9.3 million hours respectively (23).
Bottleneck removal on I-17 between Union Hills Drive and Van Buren Street by adding auxiliary lanes decreased morning peak
hour travel time by 1,384 passenger-hours (6%) (52).
Bottleneck removal on I-10 between 99th Avenue and 32nd Street by widening EB I-10 decreased morning peak travel time by
2,555 passenger-hours (13%) (52).
Bottleneck removal on SR-51 between Cactus Road and Van Buren Street by adding auxiliary lanes decreased morning peak hour
travel time by 2,686 passenger-hours (8%) (52).
Bottleneck removal on I-10 Eastbound between 24th Street and Baseline Road by constructing an EB collector-distributor road
decreased evening peak hour travel time by 4,671 passenger-hours (37%) (52).
• Efficiency: As part of the T-Rex Project in Denver, bottlenecks on I-25 and I-225 were removed by the adding lanes on the
interstates and Denver residents are now saving about 1.5 million gallons of motor fuel and related air pollution that is worth about
$4 million per year (18).
Geometric Improvements (Interchange, Ramp, Intersections, Narrow Lanes, Temporary Shoulder Use)
• Safety: 13 case studies in Texas of minor geometric improvements showed an average reduction of 35% on injury crash rates (24).
• Mobility: Assessment of temporary shoulder use a.k.a hard shoulder lane in Netherlands since 2003 revealed increased overall
capacity by 7% to 22% (depending on usage levels) , decreased travel times by 1 to 3 minutes with increasing traffic volumes up to
7% during congestion periods (25).
• Efficiency: 13 case studies in Texas of minor geometric improvements showed b/c ratios from 400:1 to 9:1 (24).
Strategy: 5.2. Access Management
Category: 5. Infrastructure Improvements and Optimization
TREATMENTS AND IMPACTS:
Access Management (Driveway location, Raised Medians, Channelization, Frontage Road)
• Safety: A research undertaken by the Kentucky Transportation Center estimated that access management could reduce total
statewide annual crash by over 20% (36).
ADDITIONAL DESCRIPTION AND QUANTITATIVE BENEFITS OF TRAVEL-TIME RELIABILITY STRATEGIES Page F-33