5 Ways WellSynchronized. Signals Increase Intersection Safety. By Dr. Reggie Chandra, PE, PTOE

Transcription

1 5 Ways WellSynchronized Signals Increase Intersection Safety By Dr. Reggie Chandra, PE, PTOE 1

2 The World Health Organization (WHO) calls traffic injuries a global public health problem, citing a human cost of 1.27 million lives lost per year in automotive collisions and other traffic accidents. 1 Governments and the traffic industry are investing in the safety of signalized roadways, including vehicle-to-vehicle and vehicle-to-infrastructure initiatives. With the advent of collision avoidance systems, the automobile industry, the United States Department of Transportation (USDOT) and the traffic control industry are making significant advancements in intersection safety. These systems rely on vehicle-to-vehicle, onboard-vehicle, and vehicle-to-infrastructure device communications. However, it will take many years before the needed technology is in place to make these systems possible. In the meantime, steps are being taken to help address this safety problem through the increasing adoption of traffic adaptive signal control systems. Here are five ways well-synchronized signals can increase intersection safety. 2

3 1. Synchronized Signals Reduce Accidents The Strategic Highway Safety Plan (SHSP) developed by the American Association of State Highway and Transportation Officials (AASHTO), along with other highway safety organizations, identified accidents at or near intersections as a particularly important challenge. Among the strategies suggested in this plan are optimizing clearance intervals and employing signal coordination. Both are categorized under the objective of reducing the frequency and severity of intersection conflicts through traffic control and operational improvements. 2 According to the National Cooperative Highway Research Program (NCHRP), traffic adaptive control solutions reduce the likelihood of accidents at intersections through reductions of some efficiency-related performance measures, which highly correlate with some safety metrics (e.g., a reduction in the number of stops reduces the chance of rear-end collisions). 3 In addition, the Crash Mitigation Factor (CMF) Clearinghouse attributes a 93.6% CMF to signal coordination. 4 The NCHRP, the Federal Highway Administration (FHWA) and other highway safety agencies recommend adaptive traffic control and signal coordination as a proven, cost-effective method of reducing vehicular collisions at or near intersections. 3

4 2. Synchronized Signals Reduce Costs In 2009, of the 33,808 reported fatalities on US roadways, 7,043 or around 21%, were intersection related, according to a report on intersection safety by the FHWA.. In 2016, the reported number of fatalities was up to 40,200, a 6% increase from 2015 alone. The report also sites that on average, there are five crashes at intersections every minute and one person dies every hour of every day at an intersection somewhere in the US. It follows then that the improvement of intersection infrastructure should be a priority in reducing the human and economic costs of traffic collisions. 5 Beyond the lives cut short is the financial toll of fatal collisions, which cost the nation an estimated $6 million per fatality. The cost of non-fatal injury crashes, although comparatively less, is $126,000 per crash Synchronized Signals Facilitate Green Tunnels, Resulting in Less Stops The FHWA Office of Safety lists nine specific countermeasures to reduce crashes within the focus areas of intersections, pedestrians and roadway departures. One area identified is too much slowing and stopping along corridor due to turbulent traffic flow. The solution: change signal control from pretimed to actuated. In addition, adaptive control dynamically assigns green time for each phase based upon system detection, 7 allowing for platoons of cars to travel through the intersections with minimal or no stops.the FHWA recognizes the reduction of traffic collisions associated with signal coordination, confirming that reducing stops not only eliminates opportunities to run red lights, but also lessens the desire to squeeze the lemon or best a red light. Optimizing clearance intervals and employing signal coordination both categorized as reducing the frequency and severity of intersection conflicts through traffic control and operational improvements, according to the Federal Highway Administration report Proven Safety Countermeasures. 4

5 4. Synchronized Signals with Adaptive Traffic Control Technologies Reduce Travel Time, Resulting in Less Road Rage The NCHRP, the FHWA and other highway safety agencies recommend adaptive traffic control and signal coordination as a proven, cost-effective method of reducing vehicular collisions at or near intersections Actuated traffic signals and traffic signal systems control (intelligent signal systems) provide better service to all movements at an intersection, reducing driver frustration and the likelihood of red-light running. 8 The National Traffic Signal Report Card notes no one appreciates getting a green light at one intersection only to get a red light at the next intersection. No one should have that experience simply because the intersections are not coordinated or the timing has not been reviewed in 10 years. 9 By reducing the number of stops along a corridor, motorists are able to get to their destinations on time and the frustrations that can lead to read rage can be reduced or eliminated. 5. Synchronized Signals with Adaptive Control Reduce Red-Light Running According to a presentation on Safety Consideration and Road Design on Urban Streets, redlight running is the most common type of accident to occur in urban areas and upwards of 700 people are killed in red-light running accidents and an estimated 165,000 are injured annually. 10 Traffic adaptive systems produce safety benefits by reducing the conditions that lead to accidents, including red-light running, which increases the likelihood of right-angle collisions. By decreasing the number of stops, queues and delays through optimizing service at each individual intersection, these systems create progression where possible. 5

6 As an adaptive traffic control system, In Sync, by Rhythm Engineering, gathers traffic data, analyzes it, optimizes it, and adapts the signal timings in real time, every second, to changing traffic demand. In Sync is able to synchronize traffic signals, reducing stops, delays and travel time to dramatically improve safety. Case Studies Evidence from the following four case studies provide feedback on the safety benefits of In Sync adaptive traffic control deployments in Virginia; Columbia County, GA; Topeka, KS; and Springdale, AR. In all four cases there was a reduction in stops, delay and travel time as well as a subsequent decline in accidents. 6

7 The State of Virginia The Virginia Department of Transportation (VDOT) had a large challenge to face: they wanted to alleviate traffic flow issues in 13 different corridors across 11 jurisdictions in the state, each with a unique structure, volume, speed limit and control need. In Sync was deployed at 111 intersections from A Virginia Center for Transportation Innovation & Research study after the deployment of In Sync found large reductions in stops, travel time and delay, as well as a 17% decreases in total accidents across the state. We have seen a clear improvement in traffic flow, and we anticipate a significant reduction in crashes. Thanks for a job well done. Don DeBerry, PE Senior Engineer City of Lynchburg, Virginia 68% Decreased Stops 17% Decreased Accidents 59% Increased Average Speed $33.7 Million in Annual Savings 37% Decreased Travel Time 7

8 Columbia County, Georgia Coordinating and optimizing signal performance on high-volume, intersecting arterials is one of the more challenging tasks for a traffic engineer. In 2009, Columbia County, Georgia deployed In Sync at five intersections along two corridors Washington Road and Belair Road. A before-and-after study revealed significant reductions in stops, travel time and delay on Washington Road, a corridor with an average daily traffic (ADT) of 40,000. Along with that, the county s traffic engineer Glen Bollinger compared crash data from the year before and after deploying In Sync, finding a 26% reduction in total crashes and a 31% reduction in crashes at intersections. These guys are great to deal with they re easy to talk to, they understand your problems, and they give you advice. Matt Schlachter Division Director Columbia County, Georgia 100% Decreased Stops 82% Reduced Delay 93% Increased Average Speed 48% Reduced Travel Time 32% Reduced Fuel Consumption 39% Reduced Emissions 26% Decreased Accidents $2.87 Million in Annual Savings 8

9 Topeka, Kansas In January 2011, the City of Topeka, Kansas installed InSync at seven intersections along 21st Street, a corridor with an ADT of 25,311, replacing its previous coordinated fixed-timing plan to improve signal operations and conserve energy. This deployment was a portion of a 22 intersection project funded by a U.S. Department of Energy grant; however, the benefits reach beyond the scope of fuel conservation alone. The optimizations of traffic flow that lowered emissions in Topeka also reduced the total number of crashes and especially reduced rear-end collisions as compared to the previously operating coordinated timing plans. According to Linda Voss, City Engineer for Topeka, after In Sync there was a reduction of 24% fewer crashes. The number of stops is way down, the congestion is way down, and it s a lot safer. Linda Voss, PE Traffic Engineer City of Topkea, Kansas 100% Decreased Stops 78% Reduced Delay 96% Increased Average Speed 49% Reduced Travel Time 36% Reduced Fuel Consumption 47% Reduced Emissions 24% Decreased Accidents $2.08 Million in Annual Savings 9

10 Springdale, Arkansas In April 2010, the City of Springdale, Arkansas installed InSync at eight intersections along Thompson/Highway 71B, a three-mile corridor with an ADT of 32,987. The Springdale Police Department reported InSync reduced crashes on the corridor by 30% based on crash data for the 12 months before and 12 months after the InSync installation. The police department data indicate there were 61 accidents in the 12 months prior to the installation date and 44 accidents during the 12 months afterward. The Rhythm Engineering adaptive solution is a fresh look at how to handle the age-old problem of how to move traffic more efficiently. Dub Janczs Signal Supervisor City of Springdale, Arkansas 95% Decreased Stops 86% Reduced Delay 73% Increased Average Speed 42% Reduced Travel Time 26% Reduced Fuel Consumption 35% Reduced Emissions 30% Decreased Accidents $5.08 Million in Annual Savings 10

11 Conclusion Conclusions from an Institute of Transportation Engineers (ITE) study, Benefits of Retiming Traffic Signals, the benefits of an A-level traffic system include reductions in traffic delay ranging from 15-40%; reductions in travel time up to 25%; and reductions in stops ranging from 10-40%. 11 Based on customer feedback, Rhythm Engineering s breakout product In Sync has proven to exceed these predictions through by revolutionizing traffic flow. Implementing an adaptive traffic control system improves intersection safety, and therefore makes it a life-saving system. Synchronized signals with adaptive traffic control create benefits that are monumental. Reduced accidents, reduced costs, reduced travel time, less road rage and reduced red-light running are just some of the immediate implications found in communities who prioritize synchronized signals. In conclusion, Rhythm Engineer s In Sync adaptive traffic control truly creates a positive impact to the lives of motorists in communities who deploy it. 11

12 Dr. Reggie Chandra, PE, PTOE spent a large portion of his career as a public traffic engineer focused on optimizing and synchronizing signals. He grew frustrated with the tools available for him to perform his job. Dr. Chandra knew the traffic signal technology had fallen decades behind, creating crowded and unsafe roadways, smog, and wasted time and fuel. He also knew traffic engineers alone didn t have all the answers. In 2005, Dr. Chandra set out to find a solution. In February of 2008, his team flipped the switch on an artificially intelligent, digital, adaptive traffic signal system that could optimize signals to automatically adapt to traffic in real time. Since its launch, In Sync has become the most widely adopted adaptive traffic control systems in the United States. More U.S. traffic agencies select In Sync than any other adaptive traffic control system, making it the fastest growing such system in U.S. history. As of January 2015, In Sync is the solution of choice for more than 1500 intersections in 29 states. Independent studies prove that In Sync reduces stops by up to 90%, cuts fuel consumption and emissions up to 30%, and even reduces accidents by up to 30%. Dr. Chandra currently serves as the Founder, President and CEO of Rhythm Engineering, LLC. The company has ranked twice on the Inc. 500 list of the fastest growing private companies in the U.S. Born and raised in India, Dr. Chandra came to the United States with his wife Jenny at the age of 27 to pursue the American dream. He earned a bachelor s degree in civil engineering, a master s degree in traffic engineering (Univ. of Florida) and a Ph.D. in organizational leadership (Regent University). In 2012, Dr. Chandra released his first book, Shades of Green: Why Traffic Signals Frustrate You and What You Can Do to Fix Them. This book explains how traffic signals work and how we can fix the problem of unsynchronized traffic signals. Dr. Chandra enjoys international travel with his friends and family, and finding ways to give back to society such as making dreams come true for adults facing life-threatening illness via The Dream Foundation, and also supports the Community Services League. He is a member of the Mid American Regional Council (MARC). He lives in Loch Lloyd, Missouri. 12

13 Citations 1. World Health Organization. The State of Road Safety Around the World. Global Status Report on Road Safety, American Association of State and Highway and Transportation Officials (AASHTO). AASHTO Strategic Highway Safety Plan. Washington DC, USA; AASHTO, NCHRP Synthesis 403, Adaptive Traffic Control Systems: Domestic and Foreign State of Practice, National Cooperative Highway Research Program, Transportation Research Board, Washington, DC, USA, Crash Mitigation Factors Clearinghouse. Study Details: Safety Effect of Arterial Signal Coordination 5. Federal Highway Administration. Intersection Safety Report. 6. Copeland, Larry, AAA: Fatal Vehicle Crash Costs $6 million. USA Today, November 3, FHWA Safety Program Signalized Intersections Informational Guide - US Department of Transportation, July 2013, Publication No. FHWA- SA FHWA Safety Program Signalized Intersections Informational Guide - US Department of Transportation, July 2013, Publication No. FHWA- SA National Traffic Signal Report Card: Executive Summary. National Transportation Operations Coalition Li, Wei and Andrew P. Tarko. Safety Consideration and Road Design on Urban Streets. Presentation at the 4th International Symposium on Highway Geometric Design, Valencia, Spain, June 5-9, Benefits of Retiming Traffic Signals. Washington DC: ITE