6.2 Improved Connections to Freeway System

Enhance the attraction of using park-and-ride facilities.

Description

A direct connector ramp between park-and-ride facilities and a freeway is an enhancement of the service provided by the parking facility. Some emissions will be reduced as buses, vans, and carpools idle less while waiting to enter and exit the freeway. This strategy serves to enable park-and-ride facilities and improves public transit.

This measure is also more expensive than others. The location of the parking facility relative to the freeway will determine the cost of constructing the ramp. Parking facilities adjacent to highways, requiring little site preparation, should demand less funding than others in more remote locations.

Application

Urban areas with park-and-ride facilities, transit service, and rideshare programs.

$$\text{Daily Emission Reduction (grams/day)} = A + B$$

$$A = (\mathit{VMT}_{\mathit{BUS},B} \times \mathit{EF}_{B} - \mathit{VMT}_{\mathit{BUS},A} \times \mathit{EF}_{A}) + (\mathit{VMT}_{\mathit{AUTO},B} \times \mathit{EF}_{B} - \mathit{VMT}_{\mathit{AUTO},A} \times \mathit{EF}_{A})$$

Reduction in vehicle running exhaust emissions from improved travel time from park-and-ride facility to freeway entrance

$$B = N_{P} \times F_{\mathit{AT}} \times \mathit{TL}_{\mathit{PR}} \times \mathit{EF}_{B} \times 2 \ \text{trips/day}$$

Reduction in auto running exhaust emissions from a reduction in commute trip length multiplied by two trips per day (round trip)

Variables	(Unit)	Definitions
$\mathit{EF}_{A}$	(grams/mile)	Speed-based running exhaust emission factor after implementation (NOX, VOC, PM, or CO)
$\mathit{EF}_{B}$	(grams/mile)	Speed-based running exhaust emission factor before implementation (NOX, VOC, PM, or CO)
$F_{\mathit{AT}}$	(percent)	Percentage of participants who previously drove single-occupancy vehicles (SOVs)
$N_{P}$		Number of new park-and-ride participants
$\mathit{TL}_{\mathit{PR}}$	(mile)	Average trip length to park-and-ride facility
$\mathit{VMT}_{\mathit{AUTO},A}$		Vehicle miles traveled by auto after implementation
$\mathit{VMT}_{\mathit{AUTO},B}$		Vehicle miles traveled by auto before implementation
$\mathit{VMT}_{\mathit{BUS},A}$		Vehicle miles traveled by transit vehicle after implementation
$\mathit{VMT}_{\mathit{BUS}\ B}$		Vehicle miles traveled by transit vehicle before implementation

Source: Texas A&M Transportation Institute