3) 10% of students living off-campus live in close enough proximity to Pitt they walk to school. 4) All bike spaces fill up completely once a day, proportionately by faculty, staff, and student ratios. 5) The same percentage of faculty and staff walks and bikes to campus based on a calculation and assumption from FY08. 6) Students hold 5% of all parking permits and fill up 4 times all metered parking spaces in a day. 7) Faculty hold 50% of all permits, and staff holds 45% of all parking permits. 8) Only staff carpools and vanpools. 9) The remaining portion of each population takes transit to campus, which in Pittsburgh is primarily the bus. Although some of these assumptions may grossly generalize the different Pitt populations’ commuting behaviors, they provide a relationship between some of the known data in Table 15 and estimated modal distributions in Table 16. Of all categories in the GHG Inventory, calculating impacts from Pitt’s commuting continues to be one of the most challenging.
Table 16 - Pitt Commute Mode Distributions for All GHG Inventory Years Students
Bike Walk Drive Alone Carpool Bus
FY08 3.2% 38.3% 3.3% 0.0% 55.3%
FY11 4.9% 36.2% 2.8% 0.0% 56.1%
FY14 4.7% 40.2% 2.4% 0.0% 52.7%
FY17 3.3% 40.2% 2.3% 0.0% 54.2%
FY19 3.1% 48.7% 1.9% 0.0% 46.4%
Faculty
Bike Walk Drive Alone Carpool Bus
3.2% 3.2% 71.0% 0.0% 22.7%
4.9% 4.9% 63.4% 0.0% 26.8%
4.7% 4.7% 49.4% 0.0% 41.1%
3.3% 3.3% 47.5% 0.0% 45.9%
3.1% 3.1% 53.4% 0.0% 40.5%
Staff
Bike Walk Drive Alone Carpool Bus
3.2% 3.2% 29.5% 9.6% 54.6%
4.9% 4.9% 30.0% 5.2% 55.0%
4.7% 4.7% 24.7% 4.6% 61.2%
3.3% 3.3% 23.6% 4.0% 65.9%
3.1% 3.1% 22.5% 3.6% 67.7%
For FY19, attempts were made to holding the same assumptions as in the previous inventories; however, known population and mobility amenity data shown in Table 15 has shifted assumptions over subsequent inventories. Estimation of commuting impacts in the FY08 and FY11 GHG Inventories were based primarily on assumptions and incorporated only a portion of the Pitt provided data shown in Table 16. The adapted approach used in FY14, FY17, and FY19 provides a more comprehensive evaluation of the different factors influencing Pitt’s commuters’ choices, providing explainable, quantitative framework for the assessment.
24
