SAFETEA-LU Evaluation and Assessment Phase I

• Work trips = 3,929 workers in service area x 1.0% bicycle commuting mode share = 39 one-way trips. Non-work trips = 67 one-way trips
• Daily vehicle trips = (39 one-way work trips + 67 one-way non-work trips) x 2 = 212 daily trips.
• Assume average trip is half the length of the bike facility.
• Daily VMT reduction = (2 x 39 one-way trips) + (2 x 67 one-way trips) * (0.5 x 8.3 miles facility length) = 633 daily VMT reduction.

• Work trips were calculated by estimating a 1 mile service area radius around the length of the 8.3 mile facility and then calculating the proportion of the total land of the community, the total population of the community, the number of households in the community, and the number of workers per household that would be served.
• The Bicycle Commuting Mode Share was estimated using the population density for the service area and a "Percent Bike Use for Commuting" table published by MassHighway Planning Department.

• Emissions factor calculated from MOBILE5A, using 35 mph average commuter travel speed.
• VOC emissions factor = 0.819 g/mile
• NOx emissions factor = 1.672 g/mile
• Summer CO emissions factor = 5.096 g/mile

Methodology based on guidance "Estimating the Effect of Bicycle Facilities on VMT and Emissions" prepared by the Seattle Engineering Department. Documentation notes uncertainty and difficulty in estimating new bicycle riders.

• Assume new bicycle riders equivalent to 1% of current drive alone workers in surrounding census tracks: 8,939 drive alone commuters x 1% x 2 trips each = 179 new bicycle trips diverted from driving.
• Assume that commuters divert 65% of the time: 179 bicyclists x .65 = 116 average new bike trips per day during season.
• Decreased autos = 116 new bike trips / 1.4 passengers per vehicle = 83 vehicle trips reduced per day during season.
• Assume 3 mile average trip length: Decreased VMT = 83 vehicle trips reduced x 3 mile average trip length = 249 VMT reduced per day during season.

Assumes seasonal use: 6 months per year.

Emissions Factors from MACOG's Conformity Analysis from the Mobile 5A model with year 2000 socioeconomic data were used.

• Assumes an increase of 160 average total daily trips by bicycle.
• Assumes the proportion of users that formerly commuted by SOV is 0.75.
• Assumes average one-way trip distance is 4 miles.

• Daily vehicle trip reduction = 160 x 0.75 = 120 vehicle trips reduced daily.
• Daily VMT reduction = 160 added participants x 0.75 x 4 miles = 480 daily miles reduced.

• Average Fort Collins Network Vehicle speed is 25.4 mph.
• Emissions reductions calculated by multiplying VMT reduction by vehicle emissions
• VOC emissions reduction = 480 VMT x 0.00189 kg/mile = 0.9072 kg/day
• NOx emissions reduction = 480 VMT x 0.00189 kg/mile = 0.9072 kg/day
• CO emissions reduction = 480 VMT x 0.01391 kg/mile = 6.6768 kg/day

Assume the average diverted bike trip is 4 miles and the number of daily bike users in NYC increases from 120,000 before the project to 121,200 after implementation.

Auto trip reduction = 1,200 new riders / 1.33 average vehicle occupancy = 902.

Existing AADT for affected roadways in all five boroughs is 143,900. Calculate the decrease in AADT after implementation = 1,200 new bike users / 1.33 average vehicle occupancy / 0.627 short trip factor/ 0.01 diversion factor = 142,998.

VMT reduced = 902 trips reduced * 4 mile trip = 3,608 miles.

Emissions reductions calculated using the CMAQtraq program developed by NYSDOT using the "BikePed Bikeway" module. Running emissions factors were used at 25 mph in each of the boroughs of New York City. Analysis assumes 190 work days per year.