SAIC N N a a t t Bryan J. Katz, PE, PTOE i i o o n n a a l l R R o o u u n n d d a a b b o o May 24, 2005 Vail, Colorado u u t t C C o o Study Performed for: n n f f e e Roundabouts r r e e n n SAIC c c e e 2 2 0 0 0 0 5 5 TRB National Roundabouts Conference D D Traffic Control Devices Pooled Fund Study Navigation Signing for R R A A Vaughan W. Inman, PhD. F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u Problem t t C C o o n n f f e e r r e e n n c c e e 2 2 0 0 0 0 5 5 rowing and Widespread Adoption of o Standard for Navigation Signing at D D R R Roundabouts Roundabouts G N A A F F • • T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C Approach o o n n f f e e r r e e n n c c e e 2 2 0 0 0 0 5 5 onduct Laboratory Evaluation of tate of Practice Review Roundabout election of Four Representative D D R R Navigation Signage Signing Approaches for Evaluation Comprehension of Representative Signs C S S A A F F • • • T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u k t t C C r o o n n o f Alternatives f Four Signing e e r r e e n n Y c c e e 2 2 w 0 0 0 0 aryland onventional iagrammatic e 5 5 D D R R C M D A A F F • • • •N T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r e e n n c c e e 2 2 Conventional 0 0 0 0 5 5 D D R R A A F F T T Route Number Shields on One Assembly, Destination Names on Separate Guide Sign N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f Maryland e e r r e e n n c c e e 2 2 0 0 0 0 5 5 D D R R A A F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r e e n n c c e e 2 2 0 0 Diagrammatic 0 0 5 5 D D R R A A F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e New York r r e e n n c c e e 2 2 0 0 0 0 5 5 D D R R A A F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r e e n n c c e e 2 2 0 0 Evaluation Method 0 0 5 5 D D R R Lane Choice Leg Identification easure Accuracy, Latency, and Confidence A A tudy Conducted in FHWA Sign Research igns Presented in Context with NCUTCD F F – – T T Laboratory Proposed Lane Markings Groups in: 64 Participants, 16 in Each of 4 Sign Type M S S • • • • N N a a t t i i o o n n a a l l R R o o u u n articipant Reads Name n d d P a a b b o o u u t t C C o o n n f f e e r r e e n n c c e e 2 2 0 Anatomy of a Trial 0 0 0 5 5 Presses Key – Aloud Shown Until Participant Makes Lane Selection Participant Makes Leg Identification Roundabout Approach with Lane Markings Roundabout Diagram Shown Until Destination Displayed Until Participant Signs shown for 2 s Each D D R R A A F F 1. 2. 3. 4. T T n tio of a s m m r o Ite Inf s N N f a a t t i i o ield o n n h er o a a l l b R R o o m te S u u n n u d d o a a Nu b b R o o u u t t C C o o n n Destination f f e e r r Combinations e e n n f c c e e o s 2 2 e 0 0 er 0 0 5 5 b m 0 3 1 3 4 2 3 5 3 6 3 2 5 3 1 4 3 0 D D R R Navigation Sign Route- Na A A F F Num T T N N a a t t i i o o n n a a l l R R o o (5) u u n n d d a a b b o o u u t t C C o o n n f f e e r r e e n n c c e e 2 2 0 0 0 0 5 5 D D R R A A F F T T Turn Restriction Lane Markings N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r e 1. Destination e n n c c e e 2 2 0 0 0 0 5 5 D D R R A A F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r e e n n c c e e 2 2 0 0 0 0 5 5 2. Navigation Sign(s) D D R R A A F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r e e n n 3. Lane Choice c c e e 2 2 0 0 0 0 5 5 D D R R A A F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r e e n n c c e e 2 2 0 0 0 0 5 5 D D 3b. Confidence Rating R R A A F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r 4. Leg Choice e e n n c c e e 2 2 0 0 0 0 5 5 D D R R A A F F T T N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t C C o o n n f f e e r r e e n n c c e e 2 2 0 0 0 0 5 5 D D R R A A F F T T 4b.