Climate Action Connection: Efficient Transportation

Using signal synchronization and remote monitoring and control allows the traffic system to adapt to changing circumstances. This reduces idling, as well as overall travel times, thus reducing emissions.

Community:Santa Clarita (Los Angeles County)

Population: 177,158

Summary

The City of Santa Clarita is using a variety of technologies to increase the efficiency of, and reduce costs associated with, its roadways and transportation systems. The city uses Intelligent Transportation Systems (ITS) technologies to monitor and control all of its 176 traffic signals. The city is also in the process of replacing signals and streetlights with high efficiency LED lights that will decrease energy use by as much as fifty percent.

Program Highlights

• Centralized control of all traffic signals from traffic operations center.
• Closed circuit TV cameras on 40 intersections.
• Web-based traffic information site under development.

Lessons Learned

• ITS investments increase road efficiency by allowing higher traffic volume.
• Keeping signal timing up to date with traffic data maintains efficiency.
• ITS investments are less expensive than widening roads.
• ITS gathers important information for analysis.
• ITS systems improve ability to share information with the public, which also improves efficiency.

Resources to Learn More

• For more information, contact the Santa Clarita Traffic and Transportation Planning Department. Phone: (661) 255-4942.

The Rest of the Story…

The City of Santa Clarita uses its Intelligent Transportation System (ITS) to accomplish two goals at once: reduce greenhouse gas emissions and save money. By synchronizing traffic signals, the city is able to minimize both travel and idling times, which reduces emissions of greenhouse gases and other pollutants. The city also has the ability to monitor and remotely control all of its 176 traffic signals. This allows it to change timing or reroute traffic in response to changing conditions or unexpected incidents, such as a major accident or fire, which can significantly affect the city’s transportation system.

Increasing the efficiency of its roadways has another benefit for the city. Like many cities, Santa Clarita has experienced a significant amount of growth over the past decade. By increasing the efficiency of its existing transportation system, Santa Clarita has avoided, or at least postponed, the need for expensive capital projects to widen its roads.

How ITS Works

The City of Santa Clarita has installed a network of sensors and communication cables to connect its traffic signals to a central traffic operations center. The network allows traffic managers to monitor traffic levels, along with signal status. Additionally, the city has installed closed-circuit television cameras to visually monitor about forty intersections.

The traffic operations center can reprogram signals as needed to adapt to specific circumstances. In an emergency, it can also provide emergency responders with information that helps them find the fastest route, and can provide advance notice of conditions they will encounter.

To protect the ITS network, and to ensure continuity in the event of problems, the city has installed a battery back-up system that provides up to three hours of power in the event of a power failure. The city can run the system longer than that, if necessary, using portable generators.

The city keeps the system’s timing up to date through traffic studies and re-timing the signal synchronization about every three years. Santa Clarita is developing a Web-based traffic information site that will allow residents, and others, to see congestion levels and travel times, based on the information gathered through the ITS network.

Funding

Santa Clarita installed the ITS network in three phases, over several years, using a variety of funding sources. Funding sources included federal Congestion Mitigation and Air Quality Improvement Program (CMAQ) funds, state gas tax funds, and Los Angeles County sales tax funds. The city also used funds from its general fund, along with funds from local special districts.

Related Efficient Transportation Activities

The City of Santa Clarita is in the process of converting its streetlights to energy efficient LED and has also been converting its vehicles to alternative fuels. Its street-sweepers run on propane, while the residential waste-haulers and some of its busses use compressed natural gas (CNG). The city has a CNG facility that is open to the public, and an environmentally preferable purchasing policy requiring transportation contractors to use alternative-fuel vehicles.
 

Compiled May 2009

This case story was prepared in partnership with the California Integrated Waste Management Board.