|BART survey data (2008). Top: rider home locations;
bottom: rider employment locations. Courtesy of BART.
BART has released its 2008 Station Profile Study, updating its last study from 1998. The data, which is collected from rider surveys, is BART’s version of the census. It reveals the demographic profile of BART riders, and it provides valuable information on how riders use the BART system: where they are coming from, where they are going, how they travel from their home a nearby station, and how they travel to their destination after riding BART. The data, which is available both system-wide and for each individual station, confirms what we know anecdotally about the role of urban vs. suburban stations: 81% of riders at 16th/Mission walked to BART, while merely 3% walked to Orinda; 72% of riders drive to North Concord/Martinez, but a miniscule 1% drive to Powell. I plan to do some number-crunching on the data in the future; but for now, I wanted to share some interesting results and initial impressions. In addition to clarifying how BART riders currently make use of the system, the survey data reveals how the Bay Area could better take advantage of this critical regional asset than we do today. The lesson we learn from the data is the lesson that we already knew: we need to do a better job of linking transit and land use, particularly along BART’s heavy rail metro lines. This is something that we are always talking about, and the BART surveys do suggest that the region is moving in the right direction in terms of promoting transit-oriented development. Bicycle trips from home to station bumped up from 3% to 4%, while transit trips declined from 23% to 15%. Nearly half (49%) of riders access stations by car (34% solo, 10% dropoff, 5% carpool), the same as in 1998. However, more people are now walking to BART stations from their home than they were a decade ago: 31% in 2008, compared to 26% in 1998. More people are also walking from BART to work or other destination: 74% in 2008, compared to 67% in 1998. Furthermore, at 6 major CBD stations (12th St, 19th St, Lake Merritt, Berkeley, Montgomery, Powell) and 5 other mostly urban stations (Ashby, North Berkeley, El Cerrito Plaza, Colma, and Balboa Park), home origin points increased by 10% or more, while car and transit origins decreased. More home-based pedestrian trips at downtown stations reflect a trend toward urban/downtown infill housing, epitomized by Jerry Brown’s 10K housing initiative in Downtown Oakland and San Francisco’s Rincon Hill plan.
Better Stations, Better Neighborhoods
But the survey data also shows that we can still do much better on both ends of the stick — both by augmenting service where it is needed, and by increasing density on valuable parcels adjacent to stations, in places where land use is currently not as intense as it should be. Contrast home origin locations for riders using 16th Street Mission with home origins for riders using North Concord/Martinez Station. The map on the left for 16th Street shows a dense residential population walking, biking, or taking transit to the station (median of 0.46-mile trip); the map on the right for North Concord/Martinez shows a dispersed ridership that mostly drives to the station (median of 6.04-mile trip):
Home origin locations, by mode. Left: 16th/Mission (circle = 1/2 mile radius).
Right: North Concord/Martinez (outer circle = 1 mile radius). Purple = walking,
green = bicycle; blue = transit, orange = drop off; red = car. Courtesy of BART.
The data also conveys another idea: while commuters are willing to travel a longer distance from their home to a station, they prefer their place of work to be more immediately located to a station. This principle should influence how we design transit-oriented development, and it should be taken into account in all station area specific plans that cities might prepare. To the extent that a “transit village” houses both commercial space and significant residential stock, the parcels immediately adjacent to the station are best reserved for significant office space with ground floor retail (perhaps destinational in nature, or of regional appeal), while outer parcels are well-suited for residential or mixed use, with ground floor commercial space that serves the neighborhood. All or most of this development should be located in a one-half mile radius of the station. This suggests that BART’s current practice of reserving station-adjacent land for large above-ground parking garages should be corrected at existing stations and avoided for any new stations that are built.
Filling In the Urban Core
We can also infer from the data prime locations to augment service and increase the value of the system by constructing infill stations. An infill station is under construction at West Dublin/Pleasanton, filling the long gap between Castro Valley and Dublin/Pleasanton, and that station will anchor a transit village. But we can also build infill stations to bring under-served urban neighborhoods (where there is already a transit-dependent population) into the fold of the system. BART stations are closely-spaced in the San Francisco and Oakland CBDs, but they are usually at least a few miles apart in the suburbs. This has prompted the observation that the BART system is not quite a proper urban subway, nor quite commuter rail, but rather is a hybrid of the two. Within the urban core, but outside of the CBDs, the stations are more closely-spaced than in the suburbs — but not as closely-spaced as they really ought to be to properly serve the corridor. BART’s data confirms the rule of thumb that most people are willing to walk to a station within one-half mile but become disinterested in walking distances greater than one-half mile. Ideally, then, BART’s urban stations would be spaced so that mostly everyone living on the corridor is within one-half mile of a station. That is often not the case, because the system was originally designed to facilitate quick trips from suburbs to urban CBDs that would be competitive timewise with freeway driving. The result is that many urban areas outside the CBDs, even those neighborhoods on the right-of-way, lack convenient (i.e. easy non-vehicular) access to BART.
|Courtesy of BART.|
Nowhere is this more true than in Oakland, southeast of the lake, where a roughly 7-mile segment of the BART corridor parallel to Interstate 880 and East 14th Street is served by just two BART stations, Fruitvale and Coliseum. The fabric of East Oakland grows increasingly suburban as you move toward the high-numbered avenues; but the area is still denser than most other places in BART’s domain, and it deserves better service. There is no station in the 3-mile stretch between Lake Merritt and Fruitvale, which means that BART trains whisk right past the Eastlake and San Antonio neighborhoods. This is one the densest sections of the East Bay, but the local residents are in large part not riding BART. This can be inferred from the survey data. Check out the map excerpted above; orange dots represent residential points of origin. There is a gray hole with no orange dots, roughly midway between the Lake Merritt and Fruitvale stations, indicating a lack of rider surveys from that area. A more fine-grained analysis shows that the highest density of riders using Lake Merritt Station live north of 8th Avenue; similarly, the highest density of riders using Fruitvale Station live south of 25th Avenue. The transit-dependent population that lives in the middle zone currently relies on AC Transit to get around rather than BART; but high population density, coupled with the presence of nearby commercial districts, suggest that this would be a successful infill station.
|Courtesy of BART.|
Another natural location for an infill station is 30th Street/Mission, which would close in an almost 2-mile gap between 24th Street and Glen Park, the longest stretch of BART track in San Francisco without a station. As shown at the map at right, the survey data demonstrates a hole in ridership near 30th/Mission. The hole is less pronounced than that near San Antonio — in part because of the shorter distance to nearby stations, and in part because this intersection is already a nexus of several Muni routes, many of which connect directly to 24th Street or Glen Park. Indeed, the fine-grained data shows that the densest ridership at 24th Street lives north of Cesar Chavez; similarly, the densest ridership at Glen Park lives south of Holly Park. Residents near 30th/Mission that use BART generally choose 24th Street station, but they mostly access the station via Muni or drop off, rather than by walking. The station at 30th Street would have the benefit of drawing riders from neighborhoods like Bernal Heights and Baja Noe, further removed from Mission Street, thus opening up a new cross-section of residential neighborhoods (and an additional commercial segment of Mission Street) to BART service. The station site also presents nice opportunities for transit-oriented development, both at the large Safeway parking lot and at smaller vacant lots scattered throughout the area.