Restricted Crossing U-Turn (RCUT) Intersection Concept, Case Studies, and Design Guide 2015 ITE Midwest Annual Meeting June 30, 2015 Branson, MO Wei Zhang, Ph.D., P.E. Program Manager, Intersection Safety R&D HRDS-10, Office of Safety R&D TFHRC Tel: (202)493-3317 Email: wei.zhang@dot.gov
Presentation Outline Introduction of RCUT intersection design Concept Function Classification Case studies of select rural RCUTs Balancing cost and safety in RCUT design Signalized RCUTs, condition for use Summary and discussions Q & A
RCUT Concept Credit: Bolton & Menk, Inc RCUT at US 212 & MN 284/CR 53, Cologne, MN
RCUT Function - Safety 4
About RCUT Also known as J-Turn, Superstreet, Reduced Conflict intersections, etc. It was conceived by Richard Kramer of Alabama in 1987 and later implemented in LA, MD, MN, MO, NC, and WI, etc. Currently, there are over 50 RCUT implementations in the U.S. It is one of the alternative intersection designs heavily promoted by FHWA under Every Day Count 2 (EDC2) initiative Intersection and Interchange Geometrics between 2012 and 2014. 5
RCUT Classifications Un-signalized (Rural) RCUT Without right-turn acceleration lane With right-turn acceleration lane Signalized RCUT 6
RCUT W/O Right-Turn Acceleration Lane US 212 & Mn 284/CR 53, MN Credit: Bolton & Menk, Inc
Example of RCUT Intersection Layout RCUT with Right-Turn Acceleration Lane US-15 & Old Frederick Rd, Frederick, MD 8
Signalized RCUT FHWA RCUT Informational Guide, Exhibit 1-1 9
Un-signalized RCUT Reduce and relocate conflict points Allow drivers to deal with one conflict a time Need of right-turn acceleration lane depends on major road traffic volume and speed U-Turn offset about 1,000 ft to 3,000 ft
Signalized RCUT Signal control to allow minor road right-turn Can allow or prohibit major road left-turn at the main intersection 2-phase operation in each direction of travel, good for ped. U-Turn offset 250 ft to 500 ft
Median(Michigan) U-turn is Not RCUT
HWY 169 and Co Rd 3, Belle Plaine, MN After # Crashes: Total 2009 4 0 2010 3 0 2011 0 0 Right Angle 13
US 212 & MN 284/CR 53, Cologne, MN 6 fatal and 1 major injury crashes from 2001 to 2010, No severe injury crash since converted into RCUT Credit: Bolton & Menk, Inc 14
MnDOT RCUT Deployment Plan Constructed RCI Planned RCI TH 52 and CO 9 on TV Credit: William Stein 15
RCUTs in Maryland US 15 US 301
Crash Data and Design of Existing RCUT in Maryland Locations Total No. of Crashes (Fatal / Injury) AADT Before After % (Major) Reduction Speed (mph) U-Turn Location (ft) Presence of Acc/Dec Lanes US 15 @ Old Frederick Rd 22 (1 / 21) 17 (1 / 16) 23% 21,510 55 2000 / 2500 Yes (500 ) US 15 @ College Ln 28 (0 / 28) 5 (0 / 5) 82% 21,510 55 3000 / 3000 Yes (650 ) US 15 @ Sundays Ln 12 (0 / 12) 9 (0 / 9) 25% 33,960 55 1700 Yes (500 ) US15 @ Biggs Ford Rd 47 (1/46) 11 (1 / 10) 77% 33,960 55 1700 Yes (500 ) US15 @ Willow Rd 23 (1/22) 22 (0 / 22) 4% 44,856 55 3000 Yes (500 ) US15 @ Hayward Rd 42 (1/41) 59 (0 / 59) +40% 41,960 50 1900 Yes (1200 ) Locations Total No. of Crashes (Fatal / Injury) AADT Before After % (Major) (3-year) (3-year) Reduction Speed (mph) U-Turn Location (ft) Presence and Length of Accel Lanes (ft) US 301 @ Galena Rd (MD 313) 21 (0 / 21) 2 (1 / 1) 90% 8,500 55 1500 / 1500 Yes (250 ) US 301 @ Main St (MD 18C) 3 (1 / 2) 3 (0 / 3) 0% 27,500 55 2600 Yes (500 ) US 301 @ Del Rhodes Ave (MD 456) 10 (1 / 9) 0 (0 / 0) 100% 27,400 55 2600 / 1500 Yes (300 ) US 301 @ Sudlersville Rd (MD 300) 10 (0 / 10) 2 (0 / 2) 80% 10,100 55 1500 / 1500 Yes (250 ) US 301 @ McGinnes Rd (MD 544) 3 (0 / 3) 0 (0 / 0) 100% 10,400 55 1500 / 1500 Yes (300 ) US 301 @ Ruthsburg Rd (MD 304) 9 (1 / 8) 0 (0 / 0) * 100% 19,100 55 2,600 Yes (300 ) * Based on 17-month after period
US 15 @ Old Hayward Rd, Frederick, MD
Competing Designs Grade separation Delivers mobility and safety Avg $12 million in rural area Signal Penalize major road traffic May not improve safety on highway road costs $400 K to $750 K RCUT Preserve major road capacity and increase minor road capacity Effective in reducing fatal/injury crashes Minor road traffic TH/LT re-routed extra distance for their own safety Avg $600 K, comparable to traffic signal
Cost Benefit Assessment When Selecting Improvement Designs Interchange costs 20 times more than RCUT and takes about 12 times more land Traffic signal may not solve the safety problem at high speed intersections For arterial roads with ADT up to 35,000, the safety benefit of RCUT is comparable to grade separation, but RCUT costs less than 10% of grade separation Many special access needs (farm vehicles and ped/bike) can be addressed with RCUT design if considered early on
Rural RCUT Geometric Design Rural RCUT promises very high safety return on investment Both design philosophies for rural RCUT are effective safety solutions under suitable traffic condition, but they require very different U-turn offset distances. 21
Crash Frequency Total Crashes 22
Crash Frequency Fatal & Injury Crashes 23
How the Crash Frequency Charts Were Derived Traffic and site characteristics of the 35 RCUTs Major road AADT: 5,900 to 44,856 vpd Minor road AADT: 434 to 5,000 vpd Ratio of Minor road AADT/Intersection AADT: 2% to 44% (less than 10% when major road AADT exceed 20,000 vpd) U-turn offsets for RCUTs w/o RT acceleration lane: 800 ft to 1,800 ft U-turn offsets for RCUTs w RT acceleration lane: 2,000 ft to 3,000 ft The charts were produced using representative major and minor road AADT combinations. Charts can be used for estimating crash frequencies of existing rural RCUTs or setting the desired range of U-turn offset for planned new RCUTs to achieve certain safety results. 24
Signalized RCUT - Applications Corridor application to improve arterial throughput Installed next to DDI or SPUI to better utilize the capacity potential of the high capacity interchange designs Under special conditions, may be used to tackle safety and operational problems 25
IL-13 and Camberia 26
Travel Demand at US-15 and Cambria Rd Total EB WB SB NB 12-hr Volume (Major Road) 24,728 veh 12-hr Volume (Minor Road) 2,040 veh (7.6% of total traffic)
Design Hourly Turning Movement Counts Current Year 2011 AM Peak Hour Factor = 0.77 Current Year 2011 PM Peak Hour Factor = 0.90 371 Cambria Rd 145 Cambria Rd 287 84 113 32 0 36 0 87 1363 1399 1247 1335 US-13 87 2937 0 US-13 238 3294 1 1166 0 1079 Haven Ln 0 1812 0 1574 Haven Ln 1 0 1 0 1 1 2
Design Hourly Turning Movement Counts Design Year 2030 AM Growth Rate = 2.2% per year for 20 years Design Year 2030 PM Growth Rate = 2.2% per year for 20 years 571 Cambria Rd 225 Cambria Rd 441 130 175 50 0 56 0 135 2100 2156 1934 2070 US-13 133 4513 0 US-13 363 5067 1 1785 0 1652 Haven Ln 0 2770 0 2407 Haven Ln 1 0 1 0 1 1 2
Capacity Analysis 60 1363 Year Period Movement Minor-Road Volume (vph) Conflicting Volume Near- / Far-side (vph) Capacity (vph) 2011 AM SB / LT&TH 84 1,363 / 1,079 60 1.4 2011 PM SB / LT&TH 32 1,247 / 1,574 50 0.6 2030 AM SB / LT&TH 130 2,100 / 1,652 15 8.7 2030 PM SB / LT&TH 50 1,934 / 2,407 10 5.0 v/c
2030 AM STOP (NO-BUILD) SIGNAL (PRE-TIMED 170-sec cycle) SIGNAL (ACTUATED) RCUT (PRE-TIMED) RCUT (ACTUATED) Movement Queue Length Avg / Max (ft) Throughput (vph) Travel Time (sec) Approach Delay and LOS EB LT 169 / 492 128 203 > 150 (F) EB TH 0 / 0 1683 14 0.6 (A) WB TH 0 / 0 2106 13 0.2 (A) SB LT > 1000 9 3293 > 500 (F) EB LT 57 / 251 134 91 74.2 (E) EB TH 22 / 601 1646 19 5.8 (A) WB TH 125 / 954 2101 31 17.1 (B) SB LT 52 / 225 130 87 69.6 (E) EB LT 30 / 211 134 59 42.3 (D) EB TH 47 / 773 1651 24 10.7 (B) WB TH 64 / 616 2107 26 12.5 (B) SB LT 31 / 177 133 62 44.2 (D) EB - LT 34 / 208 134 56 45.9 (D) EB TH 39 / 750 1779 20 9.0 (A) WB - TH 21 / 328 2099 16 5.4 (A) SB LT 31 / 166 132 52 43.2 (D) SB LT (UT) 14 / 160 130 35 19.8 (B) EB - LT 8 / 144 132 23.9 13.8 (B) EB TH 6 / 286 1775 13.7 3.2 (A) WB - TH 10 / 233 2108 14.7 4.2 (A) SB LT 8 / 108 131 22.8 13.5 (B) SB LT (UT) 8 / 120 132 26.6 12.4 (B) Intersection Delay and LOS v/c > 1.0 (F) 16.1 (B) 13.8 (B) 9.8 (A) 4.6 (A)
2030 PM STOP (NO-BUILD) SIGNAL (PRE-TIMED 170-sec cycle) SIGNAL (ACTUATED) RCUT (PRE-TIMED) RCUT (ACTUATED) Movement Queue Length Avg / Max (ft) Throughput (vph) Travel Time (sec) Approach Delay and LOS EB LT > 1000 172 755 > 500 (F) EB TH 0 / 0 1261 18 4.7 (A) WB TH 0 / 0 1945 13 0.2 (A) SB LT 1000 NO GAP 0 > 500 (F) EB LT 154 / 564 362 88 71.0 (E) EB TH 72 / 1307 2423 21 8.0 (A) WB TH 206 / 1072 1931 40 25.8 (C) SB LT 17 / 108 47 83 65.1 (E) EB LT 253 / 1044 348 122 105.0 (F) EB TH 132 / 1574 2432 28 14.8 (B) WB TH 48 / 499 1950 24 10.3 (B) SB LT 13 / 88 47 70 52.6 (D) EB - LT 59 / 339 353 39.3 29.2 (C) EB TH 138 / 1563 2780 21.1 10.6 (B) WB - TH 42 / 384 1946 20.7 10.2 (B) SB LT 5 / 67 48 31.1 21.7 (C) SB LT (UT) 10 / 77 48 54.1 39.8 (D) EB - LT 24 / 277 353 23.9 13.8 (B) EB TH 6 / 353 2776 13.9 3.3 (A) WB - TH 14 / 251 1948 15.9 5.4 (A) SB LT 2 / 50 48 19.0 9.7 (A) SB LT (UT) 3 / 66 48 26.1 11.8 (B) Intersection Delay and LOS v/c > 1.0 (F) 20.6 (C) 19.9 (B) 12.1 (B) 5.0 (A)
Conclusions At grade intersection improvement designs involve: re-prioritizing/re-routing of traffic movements elimination/relocation of traffic conflicts improvement of the overall intersection MOE usually some sacrifice of certain users. RCUT design improves safety by eliminating far side conflicts and relocating near side conflicts. RCUT design can increase minor road capacity while maintaining the capacity and LOS of major road Proper location of the median U-Turn opening is key in balancing mobility, safety, and cost
Conclusions - Continue Signalized RCUTs are known to be effective in improving corridor throughputs good choice for congested intersections next to DDI Suitable under constrained ROW condition for solving safety and operational problems 34
Questions? Wei Zhang, Ph.D. PE Intersection R&D Program Manager Federal Highway Administration Turner Fairbank Highway Research Center 6300 Georgetown Pike, McLean, VA 22101 202-493-3317 wei.zhang@dot.gov 35