The Impact of Sign Placement and Merge Type on Driving Behavior in Construction Zones

Transcription

1 The Impact of Sign Placement and Merge Type on Driving Behavior in Construction Zones Mahmoud Shakouri, Karthy Punniaraj, Laura H. Ikuma, Fereydoun Aghazadeh Mechanical and Industrial Engineering Louisiana State University

2 Construction zones common, dangerous 2 Drivers experience work zones every 100 miles % higher rate of crashes than non-construction zones fatalities per year 3 1 Ullman, 2004, 2 Council et al., 2000, 3 National Work Zone Safety Information Clearinghouse, 2011

3 Suggestions for improving merge safety 3 Reduce vehicles speed prior to construction zone entry 1 Incorporate forewarning sings for speed reduction 2 Use different merge layout 3 1 Paolo & Sara, 2012; Weng & Meng, 2011; 2 Migletz et al.,1999; 3 McCoy and Pesti, 2001

4 4 How can we improve construction zone safety? Needs: Understand how traffic design in construction zones impact Driver behavior Perceived workload while driving Understand how a person s typical driving behavior and personality affect driving behavior in construction zones Current objective: To determine how driver behavior and workload perception are affected by traffic design in construction zones in terms of Merge type Traffic density Traffic sign distances

5 Experimental approach 5 Develop a simulated construction work zone Conduct experiment with current drivers to assess driving behavior in the construction zone 2 merge types 2 traffic densities 3 sets of sign distances # lane changes Mean speed (mph) Acceleration/decelerat ion (m/s 2 ) Mean braking force (N) Drivers perceived workload (NASA-TLX factors)

6 Developing the simulation 6 Real-time on-road simulator Full-size passenger car Create objects and scripted behaviors

7 Conventional merge 7 (U.S. Department of Transportation, 2009)

8 Joint merge 8 (Idewu, 2009)

9 Experiment variables 9 Independent Variables Merge type (2): Conventional Joint Traffic density (2): High Low Sign distance (3): Standard 25% increase 25% decrease MANOVA (a = 0.05) for all analyses Dependent Variables 1. Number of lane changes 2. Mean speed (mph) 3. Acceleration/deceleration (m/s 2 ) 4. Mean braking force (N) 5. Drivers perceived workload (NASA-TLX factors) a) Mental demand b) Physical demand c) Temporal demand d) Effort e) Performance f) Frustration

10 Sample data: NASA-TLX pairwise comparison 10

11 Sample data: NASA-TLX ratings 11

12 Experiment procedures participant, students, male and female Age>18 with valid driver s licence 1. Informed consent, overview, demographic information 2. Driving and personality questionnaires: Manchester Driving Behavior Questionnaire, Driving Anger Expression Inventory, Bortner Type A personality Test 3. NASA-TLX pairwise comparison 4. Motion sickness assessment questionnaire 5. Driving: 12 simulations a) 2-3 minutes per simulation b) NASA-TLX ratings after each simulation c) Motion sickness questionnaire after every other simulation

13 Joint merge decreases workload 13 %

14 14 Joint merge decreases braking force

15 15 More lane changes in joint merge

16 High traffic density increases workload 16 % Low Traffic Density High Traffic Density

17 17 High traffic density reduces velocity

18 18 Increasing sign distance decreases lane changes

19 Driving behavior not affected in some cases 19 Merge type Deceleration (p=0.742) Velocity (p=0.821) Traffic density Deceleration (p=0.474) Braking force (p=0.526) Lane change (p=0.227) Sign distance Workload (all 6 components p>0.58) Deceleration (p=0.253) Braking force (p=0.073) Velocity (p=0.067)

20 Limitations and next steps 20 Limitations Each simulation time too short, but 12 trials fatiguing Number of participants Simulation s fidelity to real world driving experience Constraints Interstate-type road Day time Good weather Polite drivers Next steps Determine how driving behavior changes with Personality type (A/B Driving behavior tendencies (aggressiveness) Determine interaction effects between merge type, traffic density, and sign distance

21 21 Conclusion: Safer driving conditions and smoother traffic flows are possible Joint merge: lower driver workload, less brake force Lower density: lower driver workload Increased sign distance: fewer lane changes, perhaps less brake force and lower velocity Impact: Reduce crashes & fatalities by implementing traffic design characteristics associated with safer driving in construction zones

22 References 22 Benekohal, R. F, Orloski, R. L, & Hashmi, A. M. (1993). Drivers opinions on work zone traffic control. Transportation Quarterly, 47, Council, F. M, Khattak, A. J, & Khattak, A. J. (2000). Effects of work zone presence on injury and non-injury crashes. Accident Analysis and Prevention, 34, Idewu, Wakeel. (2009). Development and operational analysis of highway alternating merge transition zones. (PhD.), Louisiana State University. McCoy, P. T, & Pesti, G. (2001). Dynamic Late Merge Control Concept for Work Zones on Rural Interstate Highways. Paper presented at the 80th Annual Meeting of the Transportation Research Board, Washington D.C. Migletz, J, Graham, J. L, Anderson, I. B, Harwood, D. W, & Bauer, K. M. (1999). Work Zone Speed Limit Procedure. Transportation Research Record 1657,

23 References 23 National Work Zone Safety Information Clearinghouse. (2011). Work Zone Fatalities. Retrieved Jan. 4, 2013, from Paolo, Perco, & Sar, Dean. (2012). Driving Speed Behavior Approaching Road Work Zones On Two-Lane Rural Roads. Procedia - Social and Behavioral Sciences, 53(0), U.S. Department of Transportation. (2009). Manual on uniform traffic control devices for streets and highways. Washington, D.C: Federal Highway Administration. Ullman, G. (2004). Characteristics of Today s Work Zone. Washington D.C: Transportation Research Board. Weng, J, & Meng, Q. (2011). Modeling speed-flow relationship and merging behavior in work zone merging areas. Transportation Research Part C: Emerging Technologies, 19(6),