Parking Impact of Museum Expansion

This article discusses the impact of the proposed Asian Art Museum expansion on the demand for vehicle parking within Volunteer Park and the surrounding neighborhood.

The Asian Art Museum does not have any dedicated off-street parking except a small lot reserved for employees. Visitors who drive to the museum will park either in Volunteer Park, or on the street in the surrounding single-family residential zone. The only nearby commercial parking is the Diamond Parking lot at 1058 E. Mercer Street, a walking distance of 0.6 miles away.

The proposed expansion of the Asian Art Museum will generate a 54% increase in the annual public hour attendance of museum exhibits, according to a traffic study prepared by Fehr & Peers for Seattle Art Museum (SAM). Seattle’s land use code does not permit an expanded use of this type within this zone. SAM has proposed City Council action to create a special exemption in the land use code for this particular project, allowing an expansion of the non-conforming use and an exception to minimum parking requirements.

Here we discuss our concerns about the parking demand in Volunteer Park, and the results of our original research which we hope will be considered by decision makers considering this project, particularly the Landmarks Preservation Board, the City Council, and the Department of Parks and Recreation which manages the building as a park facility.

How The Traffic Study Determined Parking Adequacy

The Fehr & Peers study concluded that the additional museum parking demand “could be accommodated by available parking supplies within the Park”. This conclusion was reached as follows:

Fehr & Peers conducted observations of the parking occupancy on two days, Thursday, November 10, and Saturday, November 12, 2016. These were taken to represent “peak demand conditions for Museum, Conservatory, and Park Grounds during a typical week”. On the Saturday, the observed peak was 81 cars parked out of an estimated 156 spaces within Volunteer Park, leaving 75 spaces free (Table 3).

Fehr & Peers then created a model to estimate the additional parking demand created by the museum’s free days, and also the additional parking demand created by the 54% increase in public hour attendance created by the expansion. The model estimated a peak of 33 additional parked cars on a free day, plus an 33 additional parked cars as a result of the higher visitation created by the expansion (Tables 9 and 13). With 75 spaces found to be available at peak “typical” occupancy, this led to the conclusion that Volunteer Park could handle the peak increase in demand created by the expansion.

Questioning the Fehr & Peers Study

As the weather warmed during spring 2017, we began to notice a high demand for the available parking in Volunteer Park, even with the museum in a long-term closure. Some people had feared that Volunteer Park would go downhill with the museum closed, but happily the park has been thriving more than ever. Seattle’s growth has driven more activity everywhere on Capitol Hill, and people love to visit the inspirational landscape of Volunteer Park and all of its welcoming features, particularly the playground and wading pool which have drawn a bustling community of children and their families.

We questioned Fehr & Peers’ finding that the park contains enough parking to absorb the impact of museum expansion. Why are two days in November taken to represent the demand for parking in Volunteer Park year-round? The study made no attempt to account for higher park demand in the warmer and lighter seasons. Fehr & Peers sample period on Thursday, November 10, began 53 minutes after sunset. On the weekend sample on Saturday, November 12, it had been raining that morning before the sample period, so the grass and playground would have been thoroughly wet. This is not the time to find the typical park visitor. To consider people’s needs, we should indeed consider the typical visitor, not some arbitrarily chosen “typical week”.

Our Own Parking Study

In spring 2017 we recognized an opportunity to measure park demand independent of museum demand (the museum being in a months-long closure), during the warmer and lighter season. Between May 21 to June 23, 2017, we took 14 samples of the available parking within Volunteer Park, focusing primarily on weekend afternoons around 4:30 PM. Please refer to the document Our Parking Study for details. Relevant findings were the following:

  • We never once observed 75 parking spaces being available as measured by Fehr & Peers. The most we saw was 62 on a Wednesday afternoon, our only weekday sample.
  • On weekend afternoons there were an average of 23 parking spaces available. The median number of available spaces was 15. The mean and median occupancy were both over 80%.

There are differences in the two studies which make them hard to compare directly. Our study did not count the parking spaces reserved for people with disabilities, as Fehr & Peers’ study did. Also, we used a method (which we think is more accurate) of counting the actual number of parking spaces available, rather than estimating the total capacity based on 20-foot curb lengths and subtracting the number of observed parked cars from the total.

How Many Parked Cars Does The Museum Draw?

Fehr & Peers did not directly estimate how many parked cars are drawn by the normal operations of the museum at its current size. But using the same arrival/departure model as in the study, and using Fehr & Peers’ estimate that the museum draws 207 vehicle round trips on a typical day, we can model this as follows:

Time Period Arrival Rate Departure Rate Arrivals Departures Parking Demand
Before noon 15.00% 10.00% 31.05 20.7 10.35
12 PM 20.00% 15.00% 41.4 31.05 20.7
1 PM 20.00% 15.00% 41.4 31.05 31.05
2 PM 20.00% 20.00% 41.4 41.4 31.05
3 PM 15.00% 20.00% 31.05 41.4 20.7
4 PM 10.00% 20.00% 20.7 41.4 0
5 PM 0.00% 0.00% 0 0 0
Total 100.00% 100.00% 207 207

An apparent weakness in the Fehr & Peers model is that the number of parked cars at 4 PM is predicted to be zero, even though the museum does not close until 5 PM. Realizing this, we began including some 2:00 PM samples in our study, in addition to 4:30 PM samples on the same day. The results varied, but we did not find consistently higher park demand at 2:00 PM (see Table 2 of Our Parking Study for more details). We can estimate that the museum will draw 20 to 30 parked cars on a typical weekend afternoon, without considering either the effects of a free day at the museum, or the effects of the proposed museum expansion. Compare to our observation of a median count of 15 available spaces.

Parking Capacity Will be Exceeded, Even Without Expanding the Museum

Our findings suggest that on the majority of weekend days in the warmer season, the reopening of the museum at its present capacity (on a normal, non-free-admission day) will exceed the parking capacity within Volunteer Park and result in overflow onto neighborhood streets. Any increase in parking on a free weekend day will be absorbed by neighborhood streets. And most relevantly, each additional parked car generated by an expanded museum program will result in a net increase of one car parked on neighborhood streets.

Traffic Within the Park

We also observed (but did not quantify) higher traffic in the park associated with higher parking demand. Parking overflow will further increase traffic as people drive through Volunteer Park in an unsuccessful attempt to find a convenient parking space. We also observed cars waiting for a parking space.

Volunteer Park’s roads are not well suited to serve as access roads to large cultural facilities. The park is roughly bisected by Volunteer Park Road which has only two marked crosswalks, one near the water tower, and one near the Seward statue. A central area is paved in fancier stone which may suggest pedestrian right of way, but has no legal status, creating more confusion and risk. Increased traffic creates safety issues for people trying to simply walk through the park, who cannot reasonably be expected to walk to one of the crosswalks which are 950 feet apart.

Some of the most-used parking is along Prospect Street near the playground and wading pool. It is a benefit for children who arrive in cars to have a safe walk to the playground, as they have from the parking on Prospect Street. Expanded parking demand by the museum would displace some of these young users onto neighborhood streets where they would face greater conflicts with car traffic.


We believe that reopening the museum at its current size will generate more parking demand than can be satisfied by the parking available within Volunteer Park, on more than 50% of weekend days in the warmer season (because the demand is greater than the median availability). This will result in parking impacts in surrounding neighborhoods, which are zoned single-family, and not located in a designated urban village. Another result will be increased traffic within Volunteer Park, and vehicle conflicts with park users, as more cars park or unsuccessfully seek off-street parking.

All Seattle neighborhoods are absorbing more density as a result of the rapidly increasing population. Volunteer Park is not the right place to add increased institutional uses without off-street parking. A better choice would be the expansion floors in SAM’s downtown building, which are subsidized by the City of Seattle for museum use (via a bond guarantee).

SAM’s downtown location is well served by transit, including Metro buses, Link, and the future Center City Connector streetcar right at the front door, and also well served by commercial parking facilities. Compare with the east side of Volunteer Park which is served by only one Metro bus route, #10, for which Volunteer Park is the end of the line. Bus riders can only go southbound.

We believe we have presented enough information to conclude that Volunteer Park is not the right place for an expanded museum program without additional parking facilities. At minimum, more study is needed, with a more realistic estimate of the parking needs of Park users (which can be more easily measured during the warm season and museum closure). We hope that decision makers will agree that an expanded Museum program should not be approved without good evidence that an adequate supply of off-street parking exists.

This article was written by Jonathan Mark and the Protect Volunteer Park steering committee.


Traffic Study V4 (prepared by Fehr & Peers for SAM):

Our parking study: