Chapter 1 - Caltrans - State of California

Chapter 1 Proposed Project
• To reduce existing and forecasted traffic congestion and to eliminate the existing
freeway lane bottleneck and to reduce vehicle weaving within the project limits.
• To facilitate through vehicle trips by increasing the capacity of vehicles moving
through the regional highway system.
• To decrease travel times for travelers and promote ridesharing.
• To facilitate the efficient flow of goods and services through this area.
1.1.2 Need
Disproportionate demand is overwhelming the existing capacity of the U.S. 101 during
peak periods including weekends. The 2006 Average Annual Daily Traffic (AADT) was
calculated to be 82,000 vehicles and during peak periods, the highway is congested for
several hours a day in each direction.
Based upon regional growth studies, the population of Ventura and Santa Barbara County
is expected to increase. The population in Ventura County is expected to increase by 26
percent from 753,197 in 2000 to 951,080 in 2025 [Southern California Association of
Governments (SCAG) 2001 Regional Growth Trends] and the population of Santa
Barbara County is expected to increase by 20 percent from 417,500 in 2005 to 459,600 in
2020 (SBCAG Regional Growth Forecast 2007).
In addition to population growth, long distance commuting is escalating as affordable
housing is located farther away from employment centers, resulting in an increase in the
number of people commuting from Ventura County to Santa Barbara County. Surveys
indicate over 15,000 vehicles commute daily from Ventura to Santa Barbara (SBCAG
2002 Commuter Profile Survey). The coastal location, natural amenities, and temperate
weather have made this area a popular tourist destination, resulting in temporary traffic
increases on weekends and during the summer. Without improvements to the existing
highway, population growth and increasing travel demand would present even greater
challenges to an already overtaxed transportation facility. Current congested conditions
would continue to cause delay for local traffic, transit, commercial trucking, tourists,
commuters, and emergency vehicles.
Traffic Demand and Capacity
The quality of traffic flow can be defined in terms of level of service (LOS). The measure
used to provide an estimate of LOS is density. There are six LOS, ranging from LOS A
(free traffic flow with low volumes and high speeds, resulting in low densities) to LOS F
(traffic volumes exceed capacity and result in forced flow operations at low speeds,
resulting in high densities), refer to the Figure 1.2-1 on the next page for LOS thresholds
6 IS/EA VEN-SB US101 HOV Project