Prepared by Chuck Purvis, Metropolitan Transportation Commission, March 21, 2003

The following sections discuss relevant information about county-to-county commute patterns within the San Francisco Bay Area, and between the Bay Area and neighboring counties. The focus is on individual counties as opposed to groupings of counties. Tables show the ranking of the top five or top ten county-to-county worker flows based on various characteristics. This data is based on decennial census data for 1980, 1990 and 2000, including the Census 2000 data released March 2003. Data on county-to-county commuters by means of transportation is not yet available and is expected summer 2003.

1. Largest Bay Area Commute Markets, 2000

The largest county-to-county commute markets in the Bay Area are typically the intra-county worker flows in the largest counties: Santa Clara, Alameda, San Francisco and Contra Costa. The largest of these is the intra-Santa Clara County market, at nearly 728 thousand daily workers living-and-working in Santa Clara.

Rank	County of Residence	County of Work	Total Workers, 2000
1	Santa Clara	Santa Clara	727,900
2	Alameda	Alameda	453,900
3	San Francisco	San Francisco	322,000
4	Contra Costa	Contra Costa	254,700
5	San Mateo	San Mateo	206,100

2. Largest Bay Area Inter-County Commute Markets, 2000

Contra Costa-to-Alameda is the largest inter-county commute market in the Bay Area in 2000. Contra Costa-to-Alameda was also the largest inter-county commute market in 1990, and San Mateo to San Francisco was the largest inter-county commute market in the Bay Area in 1980.

Rank	County of Residence	County of Work	Total Workers, 2000
1	Contra Costa	Alameda	95,900
2	Alameda	San Francisco	72,000
3	San Mateo	San Francisco	71,700
4	Alameda	Santa Clara	69,700
5	San Mateo	Santa Clara	55,500

3. Largest Change in Bay Area Commute Markets, 1990-2000

The largest absolute growth in the Bay Area commute is for workers living-and-working in Sonoma County. The intra-Sonoma commute increased by 29,900 average daily commuters, or +19.4 percent, between 1990 and 2000. The other largest growing markets are also intra-county commute markets, including San Francisco (+22,100 workers), Alameda (+20,700 workers), Santa Clara (+17,300 workers) and Contra Costa (+17,200 workers).

Rank	County of Residence	County of Work	Total Workers, 1990	Total Workers, 2000	Change, 1990-2000	% Change, 1990-2000
1	Sonoma	Sonoma	154,300	184,400	29,900	+19.4%
2	San Francisco	San Francisco	299,900	322,000	22,100	+7.4%
3	Alameda	Alameda	433,200	453,900	20,700	+4.8%
4	Santa Clara	Santa Clara	710,600	727,900	17,300	+2.4%
5	Contra Costa	Contra Costa	237,500	254,700	17,200	+7.2%

4. Largest Change in Bay Area Inter-County Commute Markets, 1990-2000

The largest absolute growth in inter-county commuting is for workers residing in Alameda and commuting to jobs in Santa Clara County. This market increased by 16,600 average daily commuters between 1990 and 2000, a 31.3 percent increase. Interestingly, the reverse commute from Santa Clara residences to Alameda County jobs is the second fastest growing inter-county commute market, increasing by 12,800 daily workers, or +52.9 percent.

Rank	County of Residence	County of Work	Total Workers, 1990	Total Workers, 2000	Change, 1990-2000	% Change, 1990-2000
1	Alameda	Santa Clara	53,100	69,700	16,600	+31.3%
2	Santa Clara	Alameda	24,200	37,000	12,800	+52.9%
3	Contra Costa	Alameda	83,400	95,900	12,500	+15.0%
4	Alameda	San Francisco	60,500	72,000	11,500	+19.0%
5	San Mateo	Santa Clara	44,000	55,500	11,500	+26.2%

5. Largest Change in Bay Area Commute Markets, 1980-2000

Over a twenty year period the largest change in Bay Area commute markets is for workers living-and-working in Santa Clara County. The intra-Santa Clara commute has increased from nearly 600 thousand workers in 1980 to nearly 728 thousand workers in 2000, a 21.8 percent increase over twenty years. Intra-Sonoma and intra-Contra Costa are also showing significant increases over twenty years.

Rank	County of Residence	County of Work	Total Workers, 1980	Total Workers, 2000	Change, 1980-2000	% Change, 1980-2000
1	Santa Clara	Santa Clara	597,800	727,900	130,100	+21.8%
2	Sonoma	Sonoma	106,000	184,400	78,400	+74.0%
3	Contra Costa	Contra Costa	177,000	254,700	77,700	+43.9%
4	Alameda	Alameda	387,400	453,900	66,500	+17.2%
5	Alameda	Santa Clara	27,500	69,700	42,200	+153.5%

6. Largest Percent Change in Bay Area Commute Markets, 1990-2000

The commute markets with the largest percent increase over the 1990 to 2000 are also fairly small in overall size. This table is restricted to flows where the 1990 total worker flow is at least 500 daily workers. The largest percent increase markets are typically inter-regional commute flows, including Merced-to-Santa Clara (+406%), Monterey-to-Santa Clara (+141%) and San Benito-to-Santa Clara (+114%). The largest percent increase in intra-Bay Area commutes is the cross-North Bay commute from Solano-to-Marin (+131%). Another very interesting pattern is the near doubling of commuters residing in San Francisco County and working in Santa Clara County.

Rank	County of Residence	County of Work	Total Workers, 1990	Total Workers, 2000	Change, 1990-2000	% Change, 1990-2000
1	Merced	Santa Clara	682	3,449	2,767	+405.7%
2	Monterey	Santa Clara	2,402	5,799	3,397	+141.4%
3	Solano	Marin	1,913	4,418	2,505	+130.9%
4	San Benito	Santa Clara	3,767	8,054	4,287	+113.8%
5	Solano	Sonoma	1,105	2,334	1,229	+111.2%
6	San Joaquin	Santa Clara