Bay Area Carpools Where Most Time Was Saved: 2004-2008
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|
Minutes Saved
Per Vehicle in Peak Hour |
Change in
Minutes Saved |
| Rank |
Carpool Lane |
2004 |
2005 |
2006 |
2007 |
2008 |
2007-2008 |
2004-2008 |
|
|
Interstate 80, westbound, a.m. -
Alameda County
Bay Bridge toll plaza
(4 lanes, 0.4 to 1.0 miles) |
13 |
11 |
15 |
20 |
21 |
+1 |
+8 |
 |
Interstate 880, northbound, a.m. - Alameda County
16th Street to Bay Bridge toll plaza (1.4 miles) |
18 |
7 |
18 |
18 |
18 |
0 |
0 |
 |
U.S. 101, southbound, p.m. - Santa Clara County
Ellis Street to Guadalupe Parkway (6.9 miles) |
9 |
8 |
13 |
16 |
17 |
+1 |
+8 |
 |
Interstate 80, eastbound, p.m. - Contra
Costa County
Alameda County line
to Highway 4 (9.5 miles) |
5 |
8 |
8 |
14 |
16 |
+2 |
+11 |
 |
Interstate 880, northbound, p.m. - Alameda County
Santa Clara County line to Whipple Road (13.5
miles) |
19 |
11 |
5 |
9 |
16 |
+7 |
-3 |
|
Minutes Saved
Per Vehicle in Peak Hour |
Change in
Minutes Saved |
| Rank |
Carpool Lane |
2004 |
2005 |
2006 |
2007 |
2008 |
2007-2008 |
2004-2008 |
 |
Highway 85, northbound, a.m. - Santa Clara County
Almaden Expressway to Interstate 280 (8 miles) |
12 |
17 |
12 |
9 |
16 |
+7 |
+4 |
 |
Interstate 880, southbound, a.m. - Alameda
County
Whipple Road to Santa Clara County line (13.5
miles) |
19 |
23 |
18 |
17 |
15 |
–2 |
– 4 |
 |
Interstate 280, northbound, a.m. - Santa Clara
County
Leland Avenue to Magdalena Avenue (10.8 miles) |
14 |
7 |
17 |
16 |
15 |
–1 |
+1 |
 |
Highway 4, eastbound, p.m. - Contra Costa County
Port Chicago Highway to West of Railroad Avenue
(7.3 miles) |
6 |
12 |
4 |
14 |
14 |
0 |
+8 |
 |
Route 237, eastbound, p.m. - Santa Clara County
Mathilda Avenue to I-880/Rte 237 Jct. (6.5 miles) |
5 |
9 |
6 |
12 |
12 |
+6 |
+6 |
 |
Route 87, southbound, p.m. - Santa Clara County
U.S. 101 to Interstate 280 (4 miles) |
NA |
NA |
6 |
7 |
12 |
+5 |
NA |
Source: Caltrans District 4
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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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