2.9 Crash Prevention and Safety

A major goal of the ITS program is to improve safety and reduce risk for road users, including pedestrians, cyclists, operators, and occupants of all vehicles who must travel along a given roadway. Figure 2.9.1 depicts the current classification for collecting crash prevention and safety systems benefits and costs information. Road geometry warning systems warn drivers, typically those in commercial trucks and other heavy vehicles, of potentially dangerous conditions that may cause rollovers or other crashes on ramps, curves, or downgrades. Highway-rail crossing systems can reduce the potential for collisions at railroad crossing, including catastrophic accidents involving school buses or hazardous materials carriers. The goal of the Highway-Rail Intersection (HRI) User Service in the National ITS Architecture is to further improve safety at these crossings and improve coordination between rail operations and traffic management functions.

Intersection detection systems can reduce approach speeds at rural intersections by advising drivers of the presence and direction of approaching traffic. Pedestrian safety systems can help protect pedestrians by automatically activating in-pavement lighting to alert drivers as pedestrians enter crosswalks. Bicycle warning systems can notify drivers when a cyclist is in an upcoming stretch of roadway to improve safety on narrow bridges and tunnels. Animal warning systems can alert travelers when wildlife is in the vicinity of the roadway, or attempt to deter animals from crossing the roadway while traffic is present.

Table 2.9.1 provides information on the benefits and costs of crash prevention and safety. An assessment of the impact of these systems is indicated by using the symbols in the Impact Legend at the bottom of each page.

Table 2.9.1 – Benefits and Costs of Crash Prevention and Safety

Road Geometry Warning Systems: Ramp Rollover Warning

Benefits
Goal Area	# of Studies	Impact	Example
Safety	3	+	A ramp rollover warning system was installed at three curved exit ramps on the beltway around Washington, D.C. in 1993. On-site sensors and computers detected truck speeds, weight, and height classification, and then calculated the probability a truck would roll over as it approached. If a truck was at risk, a roadside warning sign was activated to alert drivers to slow down. Prior to deployment there were 10 truck rollover accidents at these sites between 1985 and 1990. After deployment, no accidents were recorded between 1993 and 1997.[123]
Costs
Unit Costs Database	Roadside Detection subsystem Roadside Information subsystem Roadside Telecommunications subsystem		See Appendix A
System Cost	As mentioned in the benefits example above, three automatic ramp rollover warning systems have been deployed around the Washington, D.C., Capital Beltway. The costs of this system for software, construction, calibration, commissioning, testing, and design were $166,462 for a one-lane ramp and $268,507 for a two-lane ramp. These costs were for a prototype rollover warning system.[124]		Single lane ramp cost: $166,462 (1994) Dual lane ramp cost: $268,507 (1994)

Road Geometry Warning Systems: Curve Speed Warning

Benefits
Goal Area	# of Studies	Impact	Example
Safety	1	?	An advanced curve warning system was installed on five curves along I-5 in a mountainous portion of rural northern California. A before-and-after evaluation at two sites showed a significant reduction in truck speeds on downgrades greater than 5%.[125]
(New) Customer Satisfaction	1	?	In a survey completed 10 months after installation of the northern California curve warning system described above, 70% of commercial vehicle drivers and 85% of passenger car drivers indicated the signs were useful. Sixty-nine percent of both types of drivers indicated they reduced their speed through the curves in response to the signs.[125]
Costs
Unit Costs Database	Roadside Detection subsystem Roadside Information subsystem Roadside Telecommunications subsystem		See Appendix A
System Cost	No data to report.

Road Geometry Warning Systems: Downhill Speed Warning

Benefits
Goal Area	# of Studies	Impact	Example
Safety	3	+	A dynamic truck downhill speed warning system installed on I-70 in Colorado decreased truck accidents by 13% and reduced the use of run away truck ramps by 24%.[123]
Customer Satisfaction	1	?	A small-scale study of truck drivers who experienced the dynamic truck downhill speed warning system in Colorado indicated that most drivers thought it was helpful.[126]
Costs
Unit Costs Database	Roadside Detection subsystem Roadside Information subsystem Roadside Telecommunications subsystem		See Appendix A
System Cost	A truck speed warning system was deployed on a downgrade curve along I-70 in Glenwood Canyon, Colorado. If a truck is detected (via radar) exceeding the posted speed, then the truck's speed is posted on a dynamic message sign (DMS).[53]		Estimated cost range for a single site: $25,000–$30,000 (1996)

Highway Rail Crossing Systems

Benefits
Goal Area	# of Studies	Impact	Example
(New) Safety	4	+	Installation of a "Second Train Coming" warning system at a light-rail transit grade crossing in the suburbs of Baltimore, Maryland, led to a reduction of 26% of vehicles crossing the tracks between the two trains. The number of drivers beginning to move their vehicles under the rising crossing gate before realizing a second train was approaching decreased by 86% after the system began operation. These benefits were determined by comparing data from a one-month evaluation period just before the system was installed and data from the two months immediately after installation.[16]
Mobility	2	?	The San Antonio, Texas, simulations of increased traffic volumes indicated DMS with railroad crossing delay information may decrease system delay by 7%.[10]
Customer Satisfaction	1	?	Before implementation of an automated warning system, 77% of surveyed residents in Ames, Iowa, indicated that train horns had a "negative" or "very negative" impact on their quality of life. After deployment, 82% of residents responded that the automated horn was "no problem."[127]
Energy/ Environment	2	?	Noise levels were measured at a highway-rail intersection before and after installation of the automated horn system in Ames, Iowa. Results indicated that areas impacted by noise levels greater than 80 decibels decreased by 97%.[127]
Costs
Unit Costs Database	Roadside Rail Crossing subsystem Roadside Detection subsystem Roadside Information subsystem Roadside Telecommunications subsystem		See Appendix A
System Cost	The Advanced Warning for Railroad Delays (AWARD) project was implemented as part of the San Antonio, Texas, Metropolitan Model Deployment (MMDI). The project consisted of Doppler radar and acoustic sensors deployed at selected locations of railroad tracks to detect the presence, speed, and length of oncoming trains as they approach grade crossings. Data are transmitted to the TransGuide Operations Center, where the data are analyzed and railroad delay information is communicated to travelers on existing dynamic message signs.[10]		AWARD project cost: $350,800 (1998) Annual O&M cost: $34,000 (1998)
(New) System Cost	In Groton, Connecticut, a four-quadrant gate with automatic train stop system was deployed. The system included four-quadrant gates to deter vehicles from attempting to cross as trains approached, and six inductive loop vehicle detectors to detect vehicles blocking the tracks. In the event of an obstruction, the detector system was designed to notify train operators via an in-cab signaling system. If the engineer failed to slow the train, then an automated system would stop the train.[17]		The cost of the system included equipment installed at the crossing and the in-cab signaling system: $977,000 (2001)
(New) System Cost	In northern Chicago, Illinois, an in-vehicle railroad crossing warning system was designed and deployed. When a train was detected by the track circuitry that activates the bells, signals, and gates, a transmitter would also broadcast a signal intended or any vehicle equipped with the special warning system receiver. In-vehicle receivers within a certain distance would activate and operate in one of three modes: audio, visual, or combination audio/visual. The in-vehicle receiver device was installed in 300 vehicles, including school buses, emergency vehicles (i.e., fire, police, and ambulance), and commercial vehicles that normally traveled through the study area.[17]		Total project cost including 300 in vehicle units and train detection equipment at five crossings: $679,000 (2001)

Intersection Collision Warning

Benefits
Goal Area	# of Studies	Impact	Example
Safety	1	?	A collision countermeasure system (CCS) was installed at an unsignalized, two-way, stop-controlled intersection in a rural area of Aden, Virginia. Before-and-after field data indicated the system lowered approach speeds. Safer projected-times-to-collision (PTCs) were observed after system implementation.[128]
Costs
Unit Costs Database	No data to report.
System Cost	No data to report.

Pedestrian Safety

Benefits
No data to report.
Costs
Unit Costs Database	Roadside Detection subsystem Roadside Information subsystem Roadside Telecommunications subsystem	See Appendix A
System Cost	A downtown Boulder, Colorado, intersection has been equipped with a series of four flashing in-pavement lights per lane. This high pedestrian-volume intersection is also equipped with two flashing pedestrian signs. The lights and signs are activated manually.[53]	Project cost including equipment and installation: $8,000–$16,000

Bicycle Warning Systems

Benefits
No data to report.
Costs
Unit Costs Database	No data to report.
System Cost	A Bicycle in Tunnel Warning System was deployed at a tunnel on Highway 971 near Chelan, Washington. Flashing beacons on a fixed message sign are activated when a cyclist presses a push-button, and deactivate after a preset time interval has passed. The fixed message sign reads, PEDS/BICYCLES IN TUNNEL WHEN FLASHING. The cost to implement the system was kept low due to the existing power source at the tunnel entrance.[53]	Cost to implement the system: $5,000 (1979)

Animal Warning Systems

Benefits
No data to report.
Costs
Unit Costs Database	No data to report.
System Cost	An Animal Warning System has been deployed in the Greater Yellowstone Rural Intelligent Transportation Systems (GYRITS) corridor. A transmitter is installed along the road where a high number of animal-vehicle incidents have occurred. The cost per site includes transmitter, solar pack, and installation (estimated). The cost does not include off-the-shelf in-vehicle radar detectors required to receive the signal from the transmitter.[53]	Cost per site includes transmitter, solar pack, and installation (estimated): $3,800
(New) System Cost	On the Olympic peninsula in Washington state, an animal warning system was deployed. The system was designed to alert motorists of the presence of elk by triggering a solar-powered radio activated flashing ELK X-ING warning sign when an animal equipped with a radio collar was within a quarter mile of the roadway. A federal grant was used to pay for the cost of collaring 12 lead elk (10% of herd), building and installing the radio-activated signs, and purchasing the equipment necessary to monitor the elk herd.[129]	Warning system: $75,000 (2001)
(New) System Cost	In Saskatchewan, Canada, a new technology was deployed to alert wildlife of freeway traffic and scare animals away from the road. Twenty-five wildlife warning units were placed on both sides of the road approximately every 1,000 feet along a 3.1-mile section of Highway 7. Units at each end of the array were equipped with sensors and transmitters to detect approaching vehicles and send signals to other warning units downstream, enabling them to activate warning lights and sounds to repel animals away from the roadway and oncoming traffic. The cost of the system did not include installation and maintenance costs during the two-year project.[129]	Wildlife deterrent system: $100,000 CAD (2001)

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