Safety Benefits of a Traffic Signal Designed for the Color Deficient Leonard Evans Bloomfield Hills, Michigan le@scienceservingsociety.com Jay Wiseman Bountiful, Utah footwise@hotmail.com please make sure sound is switched on THE 6th THE EYE, THE BRAIN AND THE AUTO WORLD RESEARCH CONGRESS Monday, September 16, 2013 (Presentations are 20-minutes long, plus a 10-minute Q & A - Challenge period) Devoted to adding reason and knowledge to public policy ScienceServingSociety.com Dearborn, Michigan 1

annual numbers of crashes at signalized intersections * total = 1,244,000 injury = 393,000 fatal = 2,635 * From Crash factors in intersection-related crashes (NHTSA, Sept. 2010) “There are nearly 350,000 traffic signals in the United States.” http://www.symmetricom.com/resources/newsletters/think-sync/March-2009/INTELLIGENT-TRANSPORTATION-SYSTEMS-WITH-SYNCHRONIZED-TIME-COULD-RELIEVE-MANY-TRAFFIC-JAMS/ http://www.renewableenergyworld.com/rea/news/article/2001/09/traffic-light-revolution-includes-photovoltaics-and-led-5404 http://www.chacha.com/question/how-many-traffic-lights-are-in-the-united-states [1] NHTSA. (2009). Traffic Safety Facts 2008. DOT HS 811 170. Washington, DC: National Highway Traffic Safety Administration. Available at http://www-nrd.nhtsa.dot.gov/Pubs/811170.pdf. http://www-nrd.nhtsa.dot.gov/Pubs/811170.pdf Table 29 DOT HS 811 366 September 2010 Crash Factors in Intersection-Related Crashes: An On-Scene Perspective On my C-drive Below is for study - above data for 2008 2 2

color vision deficiency – decreased ability to see color ( the incorrect term color blind is unacceptable) various forms – but most common is inability to distinguish red from green approximate prevalence in US:  7% for males  0.4% for females http://www.fhwa.dot.gov/policyinformation/pubs/hf/pl11028/chapter4.cfm 68.5% of pop has driver licenses http://www.indexmundi.com/united_states/demographics_profile.html possible safety issue when over 8 million drivers who cannot distinguish red from green are driving in nation with >> one million red/green traffic signals 3 3

In 2012 Jay Wiseman received U. S. Patent No In 2012 Jay Wiseman received U.S. Patent No. 8,154,423 TRAFFIC CONTROL SYSTEM (traffic signal lights designed for the color deficient and normal vision) Laboratory tests, designed and administered by Jay under the direction of David Strayer, found color-deficient subjects had reduced reaction time of 0.136 seconds to red https://www.google.com/patents/US20050190075 4

case 1 – novel signal D1 = v1T1 + (v12)/2A stop line speed v1 reaction time T1 D1 assume driver stops just in front of stop line by applying maximum braking producing constant deceleration A D1 = v1T1 + (v12)/2A 5 5

v2 = -A(T1 + Δ) + [v12 + 2Av1T1 + (A(T1 + Δ))2]1/2 case 1 – novel signal stop line speed v2 reaction time T2 case 2 - standard signal D2 now assume reaction time is Δ = 136 ms = T2 - T1 slower to standard signal can still arrive just in front of stop sign if travels at lower speed, v2 D2 = v2T2 + (v22)/2A because D2 = D1 we can solve for v2 obtaining v2 = -A(T1 + Δ) + [v12 + 2Av1T1 + (A(T1 + Δ))2]1/2 6 6

express as % reduction in speed, pv, given by pv = color-deficient driver can keep risk unchanged by reducing speed from v1 to v2 express as % reduction in speed, pv, given by pv = 100 x {v1+ A(T1 + Δ) - [v12 + 2Av1T1 + (A(T1 + Δ))2]1/2 }/ v1 with novel signal driver has level of safety as if he were travelling pv slower 7 7

percent change in risk = N x pv = N x 1.90 % specific example Δ = 0.136 seconds Δ = 0.136 seconds T1 = 2.5 seconds Δ = 0.136 seconds T1 = 2.5 seconds A = 16 ft/s2 v1 = 50 mph pv = 1.90 % percent change in risk = N x pv = N x 1.90 % for any crash N = 2 for serious-injury crash N = 3 for fatal crash N = 4 8 8

synthesis – benefits to color-deficient drivers Δ = 0.136 seconds leads to pv = 1.90 % all crashes injury fatal crashes at signalized intersections 1,244,000 393,000 2,635 xxx 46,028 14,541 97 number color deficient = 3.7% of population = [(7+0.4)/2]% 46,028 14,541 97 value of N 2 3 4 percent increase in risk = 1.90%*N 3.8% 5.7% 7.6% crashes preventable by novel signal 1,749 829 7.4 above for color-deficient drivers – but additional geometric cues help all – but with a lower value of Δ = 0.106 seconds 9 9

synthesis – benefits to ALL drivers Δ = 0.106 seconds leads to pv = 1.48 % all crashes injury fatal crashes at signalized intersections 1,244,000 393,000 2,635 affected population 1,244,000 393,000 2,635 value of N 2 3 4 percent decrease in risk = 1.48%*N 3.0% 4.4% 5.9% crashes preventable by novel signal 36,822 17,449 156 10 10

summary and conclusions have estimated safety benefits for color deficient population these additional geometric cues benefit all road users (like many changes designed to help older drivers - help all) https://www.google.com/patents/US20050190075 for information about signal contact Jay Wiseman footwise@hotmail.com 11