Post on 15-Oct-2020
Traffic Control Devices and Measures for Deterring Wrong-Way Movements
Thursday, November 15, 20182:00-3:30 PM ET
TRANSPORTATION RESEARCH BOARD
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Purpose
Discuss NCHRP Research Report 881: Traffic Control Devices and Measures for Deterring Wrong-Way Movements.
Learning Objectives
At the end of this webinar, you will be able to:
• Identify characteristics of wrong-way driving crashes on divided highways
• Describe methods for mitigating wrong-way driving on divided highways
NCHRP Research Report 881: Traffic Control Devices and Measures for Deterring Wrong-Way Movements
NCHRP Project 03-117
NCHRP is a State-Driven Program
– Suggest research of national interest
– Serve on oversight panels that guide the research.
• Administered by TRB in cooperation with the Federal Highway Administration.
• Sponsored by individual state DOTs who
Practical, ready-to-use results• Applied research aimed at
state DOT practitioners• Often become AASHTO
standards, specifications, guides, syntheses
• Can be applied in planning, design, construction, operations, maintenance, safety, environment
Traffic Control Devices and Measures for DeterringWrong-Way MovementsMelisa D. Finley, P.E.Texas A&M Transportation Institute (TTI)
November 15, 2018
Acknowledgements
Steve Venglar, P.E.TTI
Gene Hawkins Ph.D., P.E.Texas A&M University
Haitham Al-Deek, Ph.D., P.E.University of Central Florida
Raul Avelar, Ph.D.TTI
NCHRP Project 03-117 Objectives• Primary
• Examine characteristics of wrong-way crashes on divided highways• Determine the impact of median width and select traffic control devices on
their occurrence• Secondary
• Determine effectiveness of emerging countermeasures implemented at freeway exit ramps
Divided Highway Definition
Median Width Definition
Median Width
Median Width Threshold
DO NOT ENTER and WRONG WAY signs• Figure 2B-12 only for median widths ≥ 30 ft and does not indicate
required versus optional signs• Ambiguity surrounding
side of road forDO NOT ENTER andWRONG WAY signs
Divided Highway Multistate Dataset• High-speed (≥ 50 mph)• Developed procedure for identifying most likely wrong-way entry points
Texas(2012-2014)
Florida(2010-2013)
California(2008-2011) Total
Wrong-Way Crashes- Urban- Rural
18366
117
16010159
662838
409195214
Crash Corridors- Urban- Rural
16857
111
1429448
482127
358172186
Control Corridors- Urban- Rural
1225765
1379344
49427
308157151
Percent of Wrong-Way Crashesby Crash Severity
60%57%
32%
54%
39%42%
68%
45%
1% 1% 0% 1%0%
10%
20%
30%
40%
50%
60%
70%
80%
Texas(n=183) Florida (n=160) California (n=66) Total (n=409)
KAB CO Unknown
KAB = Killed, Incapacitating Injury, and Non-Incapacitating Injury; CO = Possible Injury and Not Injured
Percent of Wrong-Way Crashesby Lighting Condition
32% 30%
54%
35%
3% 2%
8%3%
65%68%
38%
62%
0%
10%
20%
30%
40%
50%
60%
70%
80%
Texas (n=183) Florida (n=160) California (n=66) Total (n=409)
Daylight Dawn/Dusk Night
Intersection Type at Most LikelyWrong-Way Entry Points
Intersection Type Texas(n=183)
Florida(n=160)
California(n=66)
Total(N=409)
Ramp 22 (12%) 3 (2%) 9 (13%) 34 (8%)Crossed median 2 (1%) 0 (0%) 0 (0%) 2 (<1%)Median opening only 14 (8%) 11 (7%) 3 (5%) 28 (7%)Private or business driveway- With median opening- Without median opening
21 (11%)10 (5%)11 (6%)
1 (<1%)0 (0%)
1 (<1%)
5 (8%)2 (3%)3 (5%)
27 (7%)12 (3%)15 (4%)
Three-leg intersection- With median opening- Without median opening
73 (40%)64 (35%)
9 (5%)
104 (65%)66 (41%)38 (24%)
22 (33%)16 (24%)
6 (9%)
199 (49%)146 (36%)53 (13%)
Four-leg intersection with median opening 51 (28%) 41 (26%) 27 (41%) 119 (29%)
Divided Highway Wrong-Way Entriesin Texas
90%
10% 63% entered via at-grade intersections
Median Width at Wrong-Way Entry Points with Median Openings
n=277
Type of Control in Median Openingat Wrong-Way Entry Points
n=27718% 82%
40%
43%
72%
12%
17%
Wrong-Way Driver Characteristics
60%
35%
N=315. Totals do not add to 100% due to blank entries (i.e., no gender or age reported).
6%
22%
15%14%
14%
24%<2121-2930-3940-4950-59>=60
Wrong-Way Driver Characteristics, cont.
N=315. Totals do not add to 100% due to blank entries (i.e., no age reported).
32%
24% 19%
28%
39% 40%
68%
76% 81%
72%
61% 60%
<21 21-29 30-39 40-49 50-59 >=60
Day Night
Wrong-Way Driver Characteristics, cont.• 39% alcohol entry blank• 40% tested negative for alcohol• 21% tested positive for alcohol
• More than 90% BAC level ≥ 0.08 g/dL (legal limit)• Almost 70% had a BAC level ≥ 0.16 g/dL (twice the legal limit)• Almost 25% had a BAC level ≥ 0.24 g/dL (three times the legal limit)
N=315.
Overview of Statistical Analyses• High-speed, four lane divided highways with median openings at
intersecting roadways (median width ≤ 120 ft)• Defined response variable as the probability of wrong-way crashes• Logistic regression used to model relationships with potential
explanatory variables as changes in the odds of a wrong-way crash occurring
• Odds ratio = 1; no change• Odds ratio < 1; reduction in odds• Odds ratio > 1; increase in odds
Modeling Process• Modeling stages
• Major design/operation variables• Stepwise model selection procedure for traffic control device variables• Testing of all models for variable interactions and model fit
• 4 safety models developed• Rural – all wrong-way crashes• Rural – nighttime wrong-way crashes• Urban – all wrong-way crashes• Urban – nighttime wrong-way crashes
Traffic Control Devices
Variables Related to Reduction in Odds of Wrong-Way CrashesDO NOT ENTER and WRONG WAY signs on outside ofwrong-way maneuver
Variables Related to Reduction in Odds of Wrong-Way Crashes, cont.Required ONE WAY signs
Variables Related to Reduction in Odds of Wrong-Way Crashes, cont.Wrong-way arrow markings on divided highway through lanes
Variables Related to Reduction in Odds of Wrong-Way Crashes, cont.• Centerline in median opening• Use of stop or yield lines in
median opening when interiorcontrol provided
Crash Correlation to Median WidthDependent upon presence of control in median opening
Control in Median Opening Change in Wrong-Way Crash Odds
or None
NoneIncreased by a multiplicative factor
for every additional 10 ft of median width
Effect of Median Width Without Control in Median Opening and per-site Variability
Summary of Findings• Median width and number of intersections more complex than a
single number• Greater use of ONE WAY signs (above those that are required) does
not appear to deter wrong-way movements• Treatments that appear to deter wrong-way movements
• DO NOT ENTER and WRONG WAY signs on outside of wrong-way turn• Required ONE WAY signs• Wrong-way arrow markings for through lanes• Centerline in median opening• Stop or yield lines in median opening when interior control used
Overview of Recommended Changes to MUTCD• Determination of single or separate intersections
• Remove 30-ft median width threshold• Base on opposing left-turn paths and storage
• Revised median width definition• Revised Section 2A.23 Median Opening Treatments for Divided
Highways with Wide Medians
Overview of Recommended Changes to MUTCD, cont.• DO NOT ENTER and WRONG WAY signs
• Changes to text and figures to clarify appropriate side of road for first and second signs
• Allow use of red LEDs• New section for wrong-way traffic control at divided highway crossings
• Language consolidated from other sections• Similar to Section 2B.41 for interchange ramps
Overview of Recommended Changes to MUTCD, cont.• Section 2B.32 KEEP RIGHT and KEEP LEFT signs• Section 2B.40 ONE WAY signs• Section 2B.41 Wrong-Way Traffic Control at Interchange Ramps• Section 2B.42 Divided Highway Crossing Signs• Section 3B.20 Pavement Word, Symbol, and Arrow Markings
Melisa D. Finley, P.E.Texas A&M Transportation Institute979-845-7596m-finley@tti.tamu.edu
Report available at http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3856
Today’s Speakers• Tom Heydel, Wisconsin Department of
Transportation, Tom.Heydel@dot.wi.gov• Melisa Finley, Texas A&M Transportation
Institute, m-finley@tti.tamu.edu
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