A Sketch Planning Assessment of ManagedLane Options for the I5 Freeway Corridor Master Plan

1
A Sketch Planning Assessment of Managed-Lane
Options for the I-5 Freeway Corridor Master Plan

• William R. Loudon,
• DKS Associates

2
Overview of Analysis

• Purpose
• To assess the potential of managed-lane
  strategies
• To determine what impact each could have on
  vehicular demand and LOS on I-5 in 2035
• Approach
• Sketch-planning adjustment of model results
• Optimistic but reasonable assumptions used about
  each
• Draw on reported experiences when available

3
Managed Lane Options

• High Occupancy Vehicle (HOV) Lanes
• High Occupancy Toll (HOT) Lanes
• Truck-Only Lanes

4
Potential Effects of Managed Lanes
5
HOV Lanes in US
124 HOV Facilities in the US

• National Experience

I-95
Yellow HOV Lanes Red HOT Lanes
6
Washington HOV Lanes on Six-Lane Roadways
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HOV Lanes Analysis Methodology

• Develop and apply reasonable percentages of
  HOV-eligible vehicles from peer review
• Estimate mode shift to and from employment sites
  based on reported experiences
• Estimate shift in HBW vehicle trips
• Estimate HOV and mixed-flow lanes LOS based on
  estimates of mode shift and HOV lane use

8
HOT Lanes in US

• Washington
• HOT Lanes on SR 167
• US
• I-10 (13 miles) and US 290 (13.5 miles) in
  Houston
• SR 91 (10 miles) and I-15 (8 miles) in Southern
  California
• I-394 in Minneapolis (11 miles)
• I-25 in Denver (6.5 miles)
• I-15 in Salt Lake City (38 miles)
• I-95 in Miami (21 miles)

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HOT Lanes Analysis Methodology

• Develop diversion rates from mixed-flow to HOT
  lanes based on available lane capacity
• Apply diversion rates to future forecasts of I-5
  volume with HOV to get estimates of HOT lane
  usage and mixed-flow lane usage
• Estimate HOT and mixed-flow lanes LOS based on
  estimates of HOT lane use

10
Truck-Only Lanes in US

• New Jersey Turnpike (I-95) 32 miles with toll
• California (I-5) 2.4 miles including tunnel
• Louisiana (Clarence Henry Truckway) 3.5 mile
  intermodal connector
• Massachusetts (South Boston Haul Road) 1.5 mile
  tunnel
• Six truck-only ramps, bridges (3 tolled) or
  bypasses of less than one mile
• Actually has passenger-car-only lanes.
  Passenger cars can use the truck lanes.

11
Truck-Only Lanes Analysis Methodology

• Use regional model to get estimate of truck
  volumes by time period
• Develop reasonable diversion rates for trucks
  from mixed-flow to truck-only lanes
• Estimate truck-only and mixed-flow lanes LOS
  based on estimates of truck-only lane use

12
Conclusions

• HOV and HOT lanes are worth additional
  consideration
• Truck lanes would do have sufficient benefit to
  warrant restriction

13
Conclusions (Continued)

• Sketch-planning methods can help evaluate
  managed-lane options in a cost-effective manner
  to support a phased decision-making process.
• Reported experiences from other managed-lane
  systems can be used to produce reasonable
  estimates of potential for managed-lanes options.
  
• The approach allowed for quick screening of
  options in the I-5 corridor in the initial phase
  of the master plan.