Safety Evaluation of Restricted Crossing U-Turn (RCUT or J-Turn) Projects in Louisiana Xiaoduan Sun University of Louisiana at Lafayette 2018 Louisiana Transportation Engineering Conference
Outline Project Background Crash characteristics before and after RCUT CMF and Benefit/Cost Discussion
Problems with traffic on minor roadway to high speed or major highways Complicated decision Problems for minor road vehicle Number of conflicting points Difficulty in deciding the sufficient gap (32 between to 14) two vehicles in the major road to cross or turn left at intersection Gap acceptance decision must be made twice in case of divided Major highway Decision 2 road intersection Major road Decision 1 Minor road 3
Potential Benefit of RCUT Aimed to reduce leftturn and all angle crashes Reduce crash severity Increase intersection capacity 4
Type of RCUT Intersection in Louisiana RCUT Intersection J(6) Intersection (150 ft) JJ(2) JJJ(2) 5
Summary Location District Location setting and Type of Year of AADT Highway Type Traffic Control Construction before/after US 167 at LA 699 3 Rural 4-lane divided 2-way stop 2012 17,100/19,133 LA 21 at Zinnia Road 62 Urban 4-lane divided 2-way stop 2012 24,900/24,200 Alexandria HY. at Kurthwood 8 Urban 4-lane divided 2-way stop 2011 7,067/9,367 LA 45 at 10 th street 2 Urban 4-lane divided 2-way stop 2013 38,233 /35,900 US 61 at LA 42 61 Urban 4-lane divided Signal 2013 41,900 /41,900 US 90 at Morgan Ave. 3 Urban 6-lane divided Signal 2012 59,833/56,000 US 90 at Perimeter Road 3 Urban 6-lane divided One-way stop (T) 2012 US 90 at Kol Drive 3 Urban 6-lane divided One-way stop (T) 2012 US 90 at Park Centre Road 3 Urban 6-lane divided One-way stop (T) 2012 US 90 at Girouard Drive 3 Urban 6-lane divided One-way stop (T) 2012 6
LA167 at 699 LA45 at 10 th St. US61 at LA42 LA 21 at Zinnia Dr. Alexandria Highway at Kurthwood Rd.
Location # of lanes on minor street Variation in Details # of LT lane on Main Highway Length (Mile) Signage on Minor Road U-Turn to Street or Driveway? Raised Island for LT? # of Driveways In between Speed Limit US 167 at LA 699 (rural) 2 1 0.62 NO Both no No 0 55 LA 21 at Zinnia Rd. 4 1 0.21 NO One yes, one no No 4 35 Alexandria Hwy at Kurthwood Rd. 2 1 0.65 NO Both no, but... Yes 20 55 LA 45 at 10 th Street 2 1 N/A NO 2 signalized int. No N/A 35 US 61 at LA 42 (signal) 4 2 0.51 YES Both no Yes 12 55 US 90 at Morgan Ave. (signal 6D) 4 1 0.41 YES Both no, but No 6 55 Diagrammatic Signage 8
US 90 Alexandria Directional Signage
Pavement Markings Available on all Minor Approaches except One Kurthwood Rd. at Alexandria Hwy. US 90 at Girouard Rd. Lane separator marking, 250 feet 10
Change in Crashes (3 years before and after project year) RCUT Intersections Total Crashes Fatal Crashes Injury Crashes PDO Crashes Before After Before After Before After Before After US 167 at LA 699 (4ST) 23 32 1 0 14 10 8 22 LA 21 at Zinnia Rd. (4ST) 49 35 0 0 17 7 32 28 Alexandria Highway at Kurthwood Rd. (4ST) 18 13 1 0 7 7 10 6 LA 45 at 10 th street, (4ST) 73 42 0 0 21 7 52 35 US 61 at LA 42, (4SG) 118 140 0 0 27 39 91 101 US 90 at Morgan Ave. (4SG) 132 96 0 0 47 46 85 50 Total crashes 413 358 2 0 133 116 278 387 Percent change in crashes 13% 100% 13% 13%
Crashes by manner of collisions RCUT Intersection Location Non-collision Rear end Right Angle Left turn Right Turn Sideswipe Before After Before After Before After Before After Before After Before After US 167 at LA 699 (4ST) 3 11 2 9 10 5 5 1 0 1 1 5 LA 21 at Zinnia Rd. (4ST) 1 1 20 18 11 3 11 5 3 3 3 4 Alexandria Highway at Kurthwood Rd. (4ST) 2 4 9 6 5 2 0 0 2 1 0 0 LA 45 at 10 th street, (4ST) 3 2 33 26 19 2 6 1 3 5 9 5 US 61 at LA 42, (SG) 6 11 53 69 14 8 14 10 6 7 21 29 US 90 at Morgan Ave. (4SG) 2 13 89 44 15 9 11 5 5 11 8 11 Total 17 42 206 172 74 29 47 22 19 28 42 54 Percent change +147% 17% 61% 53% +47% +28% Location (type of traffic control)
US 167 at LA 699 (2-way stop with flash light) Before After 13
Crashes by Year Year AADT Total # crashes Fatal crash Injury crash PDO 2009 16,700 6 0 5 1 2010 16,700 11 1 8 3 2011 17,900 6 0 1 5 2012 18,600 8 0 3 5 2013 18,800 14 0 6 8 2014 19,100 9 0 2 7 2015 19,500 9 0 2 7 By Manner of Collision Total Before 23 1 14 8 Total After 32 0 10 22 MANNER OF COLLISION BEFORE AFTER Non-collision 3 11 Rear end 2 9 Head-on 2 0 Right angle 10 5 Left turn 5 1 Right turn 0 1 Sideswipe 1 5 Total crashes 23 32
Before Change in Crashes at this intersection Collision Type Before After Rear-end 1 8 Before After 15
Rear-end collisions during the after years at the intersection only (1 to 8)
Sideswipe collisions during after years (1 to 5)
Non-Collisions after years (1 to 6)
LA 21 at Zinnia Intersection Before Location Before After
Stop sign Stop sign This J turn has a loon on either u turns to accommodate the heavy vehicles. 4 The distance of 4 drive ways from intersection: 1=200ft 2=480ft 3=410ft 4=230ft 3 1 2 Land use near the Intersection
Crashes by Year Year AADT Total Fatal Injury PDO 2009 24,400 12 0 5 7 2010 24,900 15 0 4 11 2011 25,400 22 0 8 14 2012 24,500 4 0 1 3 2013 24,800 7 0 1 6 2014 25,100 11 0 0 11 2015 22,700 17 0 6 11 Before 49 0 17 32 After 35 0 7 28 Total Number of crashes decreased by 29%. Injury and PDO crashes decreased as well. So do most types of crashes. By Manner of Collision Manner of Collision Before After Non- collision 1 1 Rear end 20 18 Right angle 11 3 Left turn 11 5 Right Turn 3 3 Sideswipe 3 4 Others 0 1 Total 49 35
Alexandria Highway at Kurthwood Road Before After Raised triangle island
Crashes by Year Year AADT Total Fatal Injury PDO 2008 6,000 8 1 3 4 2009 6,200 5 0 1 4 2010 9,100 6 0 3 3 2011 9,500 5 0 0 5 2012 9,900 2 0 2 0 2013 9,100 5 0 2 3 2014 9,100 6 0 3 3 Before 18 1 7 10 After 13 0 7 6 By Manner of Collision Manner of Collision Before After Non- collision 2 4 Rear end 9 6 Right angle 5 2 Others 2 1 Total 18 13
LA 45 at 10 th Street Before After
Only Stop sign post The 10 th street does not have pavement lane marking. No designated U-turn locations at both side of intersection U-turns can be made at two signalized intersections on each side with no U-turn signs Land use near intersection The intersection is near to several schools and institute. (pedestrians are expected). DEAF INSTITUTE
Crashes by Year Year AADT Total Acc Fatal Acc Injury Acc PDO Acc 2010 41,400 19 0 9 10 2011 38,100 25 0 5 20 2012 35,200 29 0 7 22 2013 35,200 22 0 5 17 2014 35,900 12 0 2 10 2015 35,900 18 0 1 17 2016 35,900 12 0 4 8 Before years 73 0 21 52 After years 42 0 7 35 By Manner of Collision Manner of Collision Before After Non- collision 3 2 Rear end 33 26 Head On 0 1 Right angle 19 2 Left turn 6 1 Right Turn 3 5 Sideswipe 9 5 Total 73 42
US 61 at LA 42 Before After
Loon/bay is provided for each U turns for accommodation of heavy vehicles. # of driveways=20 CVS Residential Area Land use near the intersection
Crashes by Year Year AADT Total Fatal Injury PDO 2010 37,800 41 0 7 34 2011 43,200 33 0 13 20 2012 44,700 44 0 7 37 2013 40,500 44 0 12 32 2014 41,300 42 0 14 28 2015 42,200 42 0 9 33 2016 42,200 56 0 16 41 Before 118 0 27 91 After 140 0 39 102 By Manner of Collision Manner of Collision Before After Non- collision 6 11 Rear end 53 69 Head On 4 6 Right angle 14 8 Left turn 14 10 Right Turn 6 7 Sideswipe 21 29 Total 118 140
Sideswipe at main intersection
More sideswipes 32
Driver s inattention Aggressive lane changing Driver s inattention
US 90 at Morgan Ave. (4SG) Before After 34
Crashes by Year Year AADT Total # crashes Fatal Injury crashes crashes PDO crashes 2009 58,100 50 0 22 28 2010 59,400 43 0 10 33 2011 62,000 39 0 15 24 2013 56,300 32 0 19 13 2014 57,000 28 0 18 10 2015 54,600 36 0 9 27 TOTAL Before 132 0 47 85 After 96 0 46 50 By Manner of Collision MANNER OF COLLISION BEFORE AFTER Non-collision 2 13 Rear end 89 44 Head-on 2 3 Right angle 15 9 Left turn 11 5 Right turn 5 11 Sideswipe 8 11 Total 132 96
Five Non-collision with J-turn 1. Driver 2 made an illegal U-turn at the J-turn intersection and in order to avoid vehicle 1 swerve off to strike the median island. 2. Large truck making left turn at the J-turn intersection, its back strike the traffic signal post. (Inattentiveness) 3. Unit 2 strike with the box panel dropped from unit 1 travelling ahead of it. 4. When making right to enter a parking lot, vehicle ran off the road to a ditch. 36
Right-Turn Collisions
LA167 at 699 LA45 at 10 th St. US61 at LA42 LA 21 at Zinnia Dr. Alexandria Highway at Kurthwood Rd.
RCUT Intersection Location Non-collision Rear end Right Angle Left turn Right Turn Sideswipe Before After Before After Before After Before After Before After Before After US 167 at LA 699 (4ST) 3 11 2 9 10 5 5 1 0 1 1 5 LA 21 at Zinnia Rd. (4ST) 1 1 20 18 11 3 11 5 3 3 3 4 Alexandria Highway at Kurthwood Rd. (4ST) 2 4 9 6 5 2 0 0 2 1 0 0 LA 45 at 10 th street, (4ST) 3 2 33 26 19 2 6 1 3 5 9 5 US 61 at LA 42, (SG) 6 11 53 69 14 8 14 10 6 7 21 29 US 90 at Morgan Ave. (SG) 2 13 89 44 15 9 11 5 5 11 8 11 Over all crashes 17 42 206 172 74 29 47 22 19 28 42 54 Percent change in crashes +147% 17% 61% 53% +47% +28% Any correlations? Location # of lanes on minor street # of LT lane on Main Highway Length (Mile) Signage on Minor Road U-Turn to Street or Driveway? Raised Island for LT? # of Driveways In between US 167 at LA 699 (rural) 2 1 0.62 NO Both no No 0 55 LA 21 at Zinnia Rd. 2 1 0.21 NO One yes, one no Yes 4 35/45 Alexandria at Kurthwood Rd. 2 1 0.65 NO Both no, but (UP) Yes 20 55 LA 45 at 10 th Street 2 1 N/A NO Two signals No N/A 35 US 61 at LA 42 4 2 0.51 YES Both no Yes 12 55 US 90 at Morgan Ave. 4 1 0.41 YES Both no, but (DN) No 6 55 Speed Limit mph
CMF for RCUT by Improved Method RCUT Intersections θ σ(θ) θ 2σ(θ) θ + 2σ(θ) US 167 at LA 699 (J) 1.37 0.297 0.776 1.964 LA 21 at Zinnia Rd. (J) 0.71 0.133 0.444 0.976 Kurthwood Rd. at Alexandria Hwy. (J) 0.37 0.209 0 0.788 LA 45 at 10 th Street (J) 0.57 0.096 0.378 0.762 US 61 at LA 42 (J) 1.18 0.120 0.94 1.42 Total 0.87 0.054 0.758 0.974 40
Cost and Benefit Analysis Source Cost Features Nicholas Fruge (District 3) $300,000 Bi-directional partial median opening with turn lanes DOTD Project (DOTD website) US 167 at LA 699 $3.5 million J turn+ resurfacing of 9.3 mile stretch LA 1 at Sugar Plantation $500,000 to 1million Proposed with bulb-out U turns US 90 in between Billeaud overpass and Wall Road US 171 at N. Perkins Ferry Road (In operation since 28 th December, 2016) $ 4.9 million Proposed Project $500,000 to 1million J turn along with Subgrade treatment, Class II base course laying 41
Louisiana Unit Cost per Crash by Severity Crash Severity Type Crash Report Injury Code Unit Cost Per crash Fatal A $1,710,561 Severe Injuries B $489,446 Moderate Injury C $173,578 Compliant Injuries D $50,636 PDO E $24,982 Source: http://wwwsp.dotd.la.gov/inside_ladotd/divisions/multimodal/highway_safety/pages/highway _Safety_Analysis_Toolbox.aspx
Benefit Cost Ratio Complete Intersection Location Reduction in Crashes by Injury Type Fatal Severe Moderate Complaint PDO Total Safety Benefit Total Construction Cost US 167 at LA 699 1 2 1 1-14 $2,563,919 $300,000 LA 21 at Zinnia Rd. 0 0 6 4 4 $1,343,940 $300,000 Kurthwood Rd. at Alexandria Hwy. 1 0-1 1 4 $1,687,547 $300,000 LA 45 at 10th street 0 0 1 13 17 $1,256,540 $300,000 US 61 at LA 42 0 1-2 -11-10 -$664,526 $300,000 US 90 at Morgan Ave 0 2 9-10 35 $2,909,104 $300,000 Overall 2 6 28-12 60 $12,109,270 $3,000,000 B/C ratio = 4.04 Cost per RCUT construction= $500,000, B/C= 2.42
Conclusion Improving roadway safety Economically justified Enhancing the intersection capacity The devil is in the detail
Thank you! Any Questions? xsun@louisiana.edu