2. Safety Benefits of a Traffic Signal Designed for the Color Deficient Devoted to adding reason and knowledge to public policy ScienceServingSociety.com Leonard Evans Bloomfield Hills, Michigan le@scienceservingsociety.com Jay Wiseman Bountiful, Utah footwise@hotmail.com Dearborn, Michigan please make sure sound is switched on

3. 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 )

4. 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 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 approximate prevalence in US:  7% for males  0.4% for females

5. 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

6. case 1 – novel signal stop line D1D1 assume driver stops just in front of stop line by applying maximum braking producing constant deceleration A D 1 = v 1 T 1 + (v 1 2 )/2A speed v 1 reaction time T 1

7. case 1 – novel signal stop line D2D2 speed v 2 reaction time T 2 case 2 - standard signal now assume reaction time is Δ = 136 ms = T 2 - T 1 slower to standard signal can still arrive just in front of stop sign if travels at lower speed, v 2 D 2 = v 2 T 2 + (v 2 2 )/2A because D 2 = D 1 we can solve for v 2 obtaining v 2 = -A(T 1 + Δ) + [v 1 2 + 2Av 1 T 1 + (A(T 1 + Δ)) 2 ] 1/2

8. color-deficient driver can keep risk unchanged by reducing speed from v 1 to v 2 with novel signal driver has level of safety as if he were travelling p v slower express as % reduction in speed, p v, given by p v = 100 x {v 1 + A(T 1 + Δ) - [v 1 2 + 2Av 1 T 1 + (A(T 1 + Δ)) 2 ] 1/2 }/ v 1

9. Δ = 0.136 seconds T 1 = 2.5 seconds specific example percent change in risk = N x p v = N x 1.90 % for any crashN = 2 for serious-injury crash N = 3 for fatal crash N = 4 Δ = 0.136 seconds T 1 = 2.5 seconds A = 16 ft/s 2 v 1 = 50 mph Δ = 0.136 seconds p v = 1.90 %

10. 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]% synthesis – benefits to color-deficient drivers Δ = 0.136 seconds leads to p v = 1.90 % value of N234 percent increase in risk = 1.90%*N3.8%5.7%7.6% crashes preventable by novel signal 1,7498297.4 above for color-deficient drivers – but additional geometric cues help all – but with a lower value of Δ = 0.106 seconds 46,028 14,541 97

11. 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 N234 percent decrease in risk = 1.48%*N3.0%4.4%5.9% crashes preventable by novel signal 36,82217,449156 synthesis – benefits to ALL drivers Δ = 0.106 seconds leads to p v = 1.48 %

12. 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) for information about signal contact Jay Wiseman footwise@hotmail.com summary and conclusions