Bay Area Carpool Lanes with
Highest Peak-Hour Usage: 2004-2008
(Click on a numbered bullet on the map above to go to a
specific segment.)
Download a high-resolution PDF of the map above.
|
Peak Hour
Carpool
Vehicles* |
Percent
Changed |
| Rank |
Carpool Lane |
2004 |
2005 |
2006 |
2007 |
2008 |
2007-2008 |
2004-2008 |
 |
Interstate 80, westbound, a.m. - Alameda County
Bay Bridge toll plaza |
3,630 |
3,490 |
3,660 |
3,670 |
3,710 |
+1% |
+2% |
 |
Interstate 80, westbound, a.m. - Alameda County
Contra
Costa County line to Powell Street |
1,480 |
1,630 |
1,650 |
1,760 |
1,600 |
–9% |
+8% |
 |
Interstate 80, westbound, a.m. - Alameda County
Flyover
from Powell Street to the Bay Bridge toll plaza |
1,350 |
1,640 |
1,470 |
1,480 |
1,600 |
+8% |
+19% |
 |
Route 84, westbound, a.m. - Alameda County
I-880 to Dumbarton
Bridge toll plaza |
1,180 |
1,220 |
1,420 |
1,410 |
1,530 |
+9% |
+30% |
 |
Interstate 80, westbound, a.m. - Contra Costa County
Route
4 to Alameda County line |
1,330 |
1,390 |
1,490 |
1,480 |
1,460 |
–1% |
+10% |
| Rank |
Carpool Lane |
2004 |
2005 |
2006 |
2007 |
2008 |
2007-2008 |
2004-2008 |
 |
Interstate 80, eastbound, p.m. - Alameda County
I-880 viaduct
to Contra Costa County line |
1,190 |
1,300 |
1,550 |
1,260 |
1,440 |
+14% |
+21% |
 |
U.S. 101, southbound, p.m. - Santa Clara County
Guadalupe
Parkway to I-280/I-680 interchange |
750 |
890 |
840 |
1,470 |
1,410 |
–4% |
+88% |
 |
Interstate 80, eastbound, p.m. - Contra Costa County
Alameda
County line to Route 4 |
1,190 |
1,020 |
1,440 |
880 |
1,340 |
+52% |
+13% |
 |
U.S. 101, northbound, a.m. - Santa Clara County
I-280/I-680
interchange to Guadalupe Parkway |
1,300 |
1,170 |
1,250 |
1,600 |
1,330 |
–17% |
+2% |
 |
Highway 101, southbound, p.m. - Santa
Clara County
San Mateo County line to Ellis Street |
910 |
790 |
1,100 |
1,080 |
1,270 |
+18% |
+40% |
Source: Caltrans District 4
*Includes buses, vanpools and motorcycles
|
Note on Data Collection Techniques:
Carpool Lanes — Time Savings and
Usage
Caltrans District 4 collects data on carpool-lane usage and travel-time
savings annually. Data on lane usage is compiled from direct
observations by people situated on the side of the freeway
adjacent to the carpool lanes. Travel-time savings are computed
by comparing travel time in the carpool lane with that in the
adjacent mixed-flow lanes during the peak morning and evening
commute hours. For carpool lanes that are not congested, travel
time is based on the speed limit on the freeway. For carpool
lanes that are congested, Caltrans drives specially equipped “floating
cars” to record travel time and speed. The same “floating
car” technique is used to measure the travel time in
adjacent mixed-flow lanes. Caltrans District 4 annually publishes
a report with complete data on carpool-lane usage and travel-time
savings. This report also includes detailed information on
the hours of operation, number of people using the carpool
lane compared to adjacent general purpose lanes, and violation
rates. The Caltrans District 4 reports can be found at: www.dot.ca.gov/dist4/reports.htm
For more information, please contact:
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