Should the Port Authority Fund Park-in-Ride Garages?

The Port Authority is redeveloping the park-in-ride serving the West Busway at Carnegie. The plan includes several good investments, including an expansion of the panhandle trail, storage for bicycles, and electric charging stations for buses.  However, a substantial portion of the public funds are going to a bad investment, parking spaces for cars. Several transit advocates and urban planners have written about how park-in-ride parking is a bad investment of public money, including this Bloomberg opinion piece, and Alon Levy here and here. This Carnegie project can make for a good case study as to why, and how the money could be spent more effectively.

The existing parking lot is a surface lot with 199 spaces. The port authority does not currently charge for parking. The proposed development would increase the total number of parking spaces to 434, a 235 space increase.

While the portion of the $\$$13 million project going to the parking expansion has not been specified, a recent development on the north side can be used to make an estimate. This article describes a plan to build an $\$$11.5 million parking garage that replaces a 134 car surface lot with a 445 car parking garage.  This equates to $\$$37,000 per additional spot. If the parking costs are equivalent per spot, $\$$8.7 million of this project will be for additional commuter parking. This figure will be assumed for the rest of this post.

The existing parking lot fills up early in the morning, but adding 235 spaces does not mean there will be that many new riders even if the new garage fills.  Many of the new riders are people who would have found nearby street parking,would have walked to a bus stop, or been dropped off given that the surface lot is full at the time they needed to commute. The bus station at this park and ride averaged 456 daily boardings in 2020 according to the system map, so a majority of the existing riders already travel to the station by means other than parking at the lot. The extra automotive traffic generated by the enlarged parking may hinder pedestrian access to the station. Therefore paying for 235 additional parking spaces will result in fewer than 235 additional bus riders. One study even found that building parking around transit stations actually increased vehicle miles traveled because more people drove rather than walk or bike to access transit as a result.

Additionally, this project may free up street parking in Carnegie by allowing people to park at the lot rather than nearby streets. This may enable more people to drive to Carnegie for purposes other than station access, further increasing traffic congestion. This would be ironic for a project primarily funded by a congestion mitigation grant.

If the Port Authority were already charging enough in the existing parking to demonstrate that the new spots could pay for themselves, this development would be defensible.  I have previously written about the benefits of charging for park-in-ride parking.

There are several transit improvements that deliver far more value than subsidized parking.

Increase Bus Service Hours

It would be less expensive per new transit passenger to add service hours for Port Authority buses for 30 years than to build garage parking.  Additional service has the advantage that the entire trip is typically made using transit, compared with parking spaces that only allow a segment of the trip to be substituted with transit.  Additionally, additional service allows people on the transit network to access the suburbs in addition to allowing suburbanites to access the city.

The most cost effective way to add service miles is to give transit vehicles signal priority, and use the time saved at intersections to either run at higher frequency or operate additional route miles.  However, even with the more expensive method of paying the operating costs of additional service hours expanded service is more cost effective than building parking.

Assuming a 2.3% interest rate, an $\$$8.7 million parking garage amortized over 30 years corresponds to $\$$33,477.71 per month or $\$$1,100 per day (or $\$$1541 per weekday if we assume the new spaces are not filled on weekends). On page 12 of the FY2020 budget, it identifies the operating cost of a bus at $\$$188.43 per revenue hour. Therefore the cost of the parking garage could pay for 8.2 hours of weekday service per day or 5.8 hours of seven-day service per day. 

The Port Authority’s 2018 annual service report states that there are on average 33.2 bus passengers per revenue service hour. So assuming that the existing parking capacity is only exceeded on weekdays, the construction cost of the parking garage could pay for bus service to transport 272 additional passengers each weekday for the next 30 years.

$8.2\ \textrm{hours}\times33.2\frac{\textrm{passengers}}{\textrm{hour}}=272 \ \textrm{passengers}$

Even if every new parking spot resulted in a new bus passenger (an assumption that greatly overstates things for the new parking), parking spots would create fewer passengers than adding bus routes that allow people to walk to a bus stop near their house for service. This is before considering maintenance costs for the garage, or operating costs for the additional busway buses to carry them.

Unfortunately, federal funding is generally only available for capital costs, not operating costs. So the federal grant that will partially fund the garage may not be available to directly fund operating costs. It may be possible to use federal funds on capital improvements that improve bus speed.  This could allow for more service miles with the same operating costs.  Traffic signal priority, bus stops with level boarding, and dedicated bus lanes are all methods to do this.

Even though adding service is more cost effective than building parking, there are still more cost effective ways to improve ridership.

Building more Bus Shelters

Bus shelters are one of the most cost effective ways to increase transit ridership. I have previously written that Pittsburgh and Allegheny County should increase their investment in bus shelters.  This article estimates that adding a shelter to a stop increases ridership from that stop by 15% and estimates the typical cost of a shelter at $15,000.

If we assume that each new parking spot at Carnegie leads to a new transit rider, or 2 one way trips per day, putting a shelter at any bus stop with more than 5.4 average daily boardings will generate more new riders for the same expenditure than the parking garage.

$\frac{2}{0.15}\times\frac{\$15,000}{\$37,000}=5.4$

As I wrote in a previous blog post advocating more bus shelters, there are numerous bus stops with over 100 daily boardings and no shelter.  At these stops you could add 15 daily riders for less than half the price of a parking spot.

Residential Development on the Parking Lot

Rather than a project that requires public funding, selling or leasing the surface lot to a developer to build a residential development would provide the Port Authority with money it could use on other transit improvements.  It may also increase ridership by more than building the surface lot.

A parking space takes about 200 ft².  Therefore you could build a 1,000 ft² apartment for every five parking spaces.  Therefore a 10 story building would contain as many apartments as a two story garage. A parking garage could be built underground for both commuters and residents, with spots leased at a market rate to incentivize residents to rely on transit and not purchase a space.

Ideally, the ground floor would have retail which would make it easier for residents to live without a car.

In such an arrangement, there would be a high mode share for transit among residents. Since residents would have such convenient access to quality transit and need to pay a premium for parking, most would only choose to live in the building if they plan to forgo car ownership or at least commute by bus.  

Many of these apartments would have more than one resident using transit, and many residents would average more than one transit round trip per day.  Therefore a 10 story apartment would likely generate more transit rides than the parking garage development. If an underground garage was built in addition paid for by leasing spaces, it would definitely generate more trips.

To reiterate, this would be for a project that generates rather than costs public money.

Transit Oriented Development

There is significantly more potential to increase ridership through residential development near the station. Unfortunately, auto-oriented zoning codes in Carnegie and elsewhere make it illegal to build the types of development that are easy to serve with good transit.

Zoning changes would allow infill development that increase ridership in locations where people can walk to the station.  I wrote a previous post describing how zoning can be reformed here.

Improving Pedestrian Infrastructure

There are streets in the walk shed of the Carnegie station that lack sidewalks. A pedestrian study has been done that identifies gaps in the sidewalk network. The Port Authority has published a document on improving accessibility to fixed guideway stations by pedestrians and cyclists.

All streets should have sidewalks, but the benefits of sidewalks are particularly high within the half mile walksheds of bus stops and stations that provide frequent service.  In addition to ensuring the presence of sidewalks, traffic calming and other safety features like crosswalks and street lighting are needed to improve both real and perceived safety. Consideration should be given with crosswalk placement and traffic signal timing to minimize the delay to pedestrians travelling to or near the station. Improving the pedestrian infrastructure will enable more people to use transit, as well as make pedestrian trips without the need of a car.

A plan for transit oriented development in the west busway area was developed in 2010.  This plan identifies numerous pedestrian improvements that can be made near the station (the discussion applicable to Carnegie starts on page 134 of the pdf). Improvements are proposed to West Main Street, 3rd Street, Jefferson street, and East Main Street including the bridge. The estimated price for all of these street improvements proposed is $9.945 million.  While this is slightly higher than the cost of the parking garage, these improvements would do considerably more to improve the transportation system.

½ Mile Walkshed around Carnegie Station

Conclusion

All of the alternatives to expanded parking described in this post would raise ridership more cost effectively than building parking spaces.  Furthermore, the additional transit rides would mostly be rides conducted entirely by transit, rather than adding trips where some of the journey is by automobile. Public money should not be spent on parking at transit stops and stations.