LESSONS LEARNED: ALTERNATIVE INTERSECTION AND INTERCHANGES CRAIG ELEY, P.E., CHOICE ONE ENGINEEING MARC GRAKE, P.E., ODOT DISTRICT 8 TRAFFIC OPERATIONS KRAIG SHREWSBERRY, P.E., PTOE, ODOT DISTRICT 6 TRAFFIC OPERATIONS
INTENDED AUDIENCE: LOCAL CITIES AND VILLAGES THAT MAY BE CONSIDERING HOW TO IMPROVE INTERSECTION OR ANY INTERCHANGE BUT HAVE LIMITATIONS OF: TIME TO GET IMPROVEMENT BUILT QUICKLY BUDGET RIGHT-OF-WAY
FOR ANY PROJECT, WHAT ARE WE TRYING TO FIX? THE TWO MAIN REASONS FOR ANY TYPE OF INTERSECTION OR INTERCHANGE PROJECT: RELIEVE CONGESTION IMPROVE SAFETY WHILE KEEPING COSTS LOW AND WITH THE FEWEST IMPACTS.
HOW DO WE RELIEVE CONGESTION? STANDARD SOLUTIONS: ADD MORE PAVEMENT TO INCREASE CAPACITY: FOR INTERSECTIONS AND INTERCHANGES, MORE TRAFFIC WILL BE ABLE TO GET THRU THE INTERSECTION BY WIDENING TO ADD MORE TURN LANES/THRU LANES. POTENTIAL DRAWBACKS: EXPENSIVE TO ADD MORE PAVEMENT. MAY HAVE TO WIDEN BRIDGES. ADDITIONAL TIME AND MONEY TO PURCHASE RIGHT OF WAY. TRAFFIC IS ALWAYS INCREASING, SO SIMPLY JUST CAN T KEEP WIDENING AND WIDENING. CAN BE A LENGTHY PROCESS.
HOW DO WE IMPROVE SAFETY? STANDARD SOLUTIONS: REDUCE BACKUPS BY ADDING MORE LANES. IMPLEMENT PROTECTED ONLY MOVEMENTS. BUILD INTERCHANGES TO SEPARATE TRAFFIC. POTENTIAL DRAWBACKS: DOESN T REDUCE THE NUMBER OF CONFLICT POINTS AT AN INTERSECTION. RESTRICTION OF MOVEMENTS DOES IMPROVE SAFETY BUT WILL DECREASE TRAFFIC FLOW. GREAT EXPENSE OF TIME, MONEY, AND RIGHT-OF-WAY.
WHY ARE WE CONSIDERING ALTERNATIVE TREATMENTS NOW? STANDARD PRACTICES OR TREATMENTS CAN BE: EXPENSIVE LENGTHY PROCESS RIGHT-OF-WAY IMPACTS: ACQUIRING PROPERTY ADDS TIME AND MONEY TO THE PROJECT. IMPROVEMENTS CAN COUNTERACT EACH OTHER: IMPROVEMENT IN SAFETY MAY MEAN SACRIFICING TRAFFIC FLOW, SO WHAT DOES THE PUBLIC SEE? SIMPLY CAN T CONTINUE TO KEEP WIDENING AND BUILDING BRIDGES.
SO HOW DO WE GET MORE VEHICLES SAFELY THRU AN INTERSECTION? HAVE TO START THINKING OUTSIDE THE BOX WE KNOW THAT REDUCING THE NUMBER OF SIGNAL PHASES AT AN INTERSECTION WILL PROVIDE MORE GREEN TIME TO THE REMAINING PHASES: (EACH MOVEMENT GETS THEIR SLICE OF THE PIE FOR GREEN TIME)
SO HOW DO WE GET MORE VEHICLES SAFELY THRU AN INTERSECTION? A STANDARD INTERSECTION HAS 32 CONFLICT POINTS WITH 16 CROSSING (LEFT TURN) CONFLICTS, SO REDUCING THIS NUMBER OF CONFLICT POINTS WILL IMPROVE SAFETY. SO REDUCING OR ELIMINATING LEFT TURN AND CROSSING MOVEMENTS SHOULD MAKE A SIGNIFICANT REDUCTION IN SAFETY. REDUCE THE NUMBER OF COVENTIONAL INTERSECTIONS-SIMPLY SAID, BUT HARD TO IMPLEMENT.
3 PROJECTS THAT USED ALTERNATIVE TREATMENTS PARTIAL CONTINUOUS FLOW INTERSECTION (PARTIAL CFI.) SR 741 @ AUSTIN BLVD IN MONTGOMERY COUNTY, DISTRICT 7. SUPERSTREET INTERSECTION. SR 4 BYPASS @ HAMILTON-MASON, TYLERSVILLE, AND SYMMES ROADS IN BUTLER COUNTY IN DISTRICT 8. SINGLE POINT URBAN INTERCHAGE (SPUI.) SR-161 @ SUNBURY ROAD IN FRANKLIN COUNTY, DISTRICT 6.
OUTLINE Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 General Overview of Continuous Flow Intersection (CFI) SR 741 & Austin Blvd Design and Operation Planning and Construction Lessons Learned / Questions 10
CONTINUOUS FLOW INTERSECTION Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA FHWA defines this type of intersection as a Displaced Left Turn Intersection (DLT). Objective is to reduce delay and increase capacity. Left turn movements occur in advance of the main CFI traffic signal at advance traffic signals placed approximately 300 to 400 feet upstream of intersection. 11 CFIs have been shown to increase capacity by 60% compared to similar conventional intersections (1996 Traffic Control Systems Handbook)
CFI ADVANTAGES AND DISADVANTAGES Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA Advantages Shorter delay and travel times Double left turn = 82.5 sec CFI = 27.4 sec Separate left turns from through traffic Improved capacity Disadvantages Adjacent Property Impacts (driveways, right-of-way, etc.) Signal Maintenance Pedestrian Accommodations 12 Driver Familiarity
DRIVER SAFETY Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA CFIs have fewer conflict points than conventional intersections Angled conflict points are also fewer in CFIs Therefore when collisions do occur they tend to be less significant and damaging. 13
CONFLICT POINTS Courtesy FHWA Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Traditional Intersection 32 conflict points 16 angle conflict points Continuous Flow Intersection 30 conflict points 14 angle conflict points 14
PEDESTRIAN MOVEMENTS AND SAFETY Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 15 Courtesy FHWA Crossing pattern similar to traditional intersection, but improvements should be made Pedestrian refuges between lanes can increase safety and minimize vehicle delay Accurate signing to guide pedestrians to their destination
ADVANCE LEFT TURN MOVEMENT Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA 16
ADVANCE LEFT TURN MOVEMENT Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA 17 Advance Left Turn Distance 300-400 Ft
TWO-LEGGED CFI EXAMPLE Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA Advance CFI Traffic Signal Center CFI Traffic Signal Advance CFI Traffic Signal 18
FOUR-LEGGED CFI EXAMPLE Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA 19 Source: FHWA Publication No.: FHWA-HRT-09-055, FHWA Contact: Joe Bared, HRDS-05, (202) 493-3314, joe.bared@dot.gov
P1 P6 P2 P5 P3 P8 P4 P7 TWO-LEGGED CFI CENTER TRAFFIC SIGNAL Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 P1 P2 P3 P4 P5 P6 P7 P8 20
AUSTIN BOULEVARD & STATE ROUTE 741 LOCATION Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA 21 Miami Township, Montgomery County, Ohio Opened fall 2010
AUSTIN BOULEVARD & STATE ROUTE 741 LAYOUT Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Courtesy FHWA 22
WHY SELECT A CFI? Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 23 Austin Boulevard at SR 741, PM Peak Hour, Design Year 2035 Current Geometry (No-Build) Overall Average Delay: 166.2 seconds Level of Service: F Eastbound/Westbound Travel Time: 3.3/1.6 minutes Current Geometry with Double Lefts, All Approaches Overall Average Delay: 65.3 seconds Level of Service: E Eastbound/Westbound Travel Time: 1.5/1.5 minutes Two-Legged CFI on Austin Boulevard (E/W) Overall Average Delay: 27.5 seconds Level of Service: C Eastbound/Westbound Travel Time: 1.3/1.6 minutes
PHASING DIAGRAM Photo taken by jyoh Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 24
25 Photo taken by jyoh OPERATION HIGHLIGHTS Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 The CFI operates utilizing: Three separate signalized locations consisting of: 34 traffic signal heads 20 pedestrian signal heads 16 Iteris Versicam video detection cameras with Edge Connect module for remote monitoring 6 single mast arm signal support poles 2 double mast arm signal support poles All controlled by: 2070 Siemens controller using Eagle Traffic software (First installation east of the Mississippi River) 16 phases 15 overlaps Photo taken by jyoh
CRASH DATA BEFORE CFI Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 26
CRASH DATA AFTER CFI Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 27
MOST RECENT CRASH DATA AFTER CFI Crashes 2013 2015 Total Crashes = 100 Rear End = 71 Angle/Left Turn =15 SideSwipe passing = 8
OPENING DAY CONDITIONS Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Photo taken by jyoh Delay and Level of Service Northbound Left Turn 92.6s / F (AM Peak) Eastbound Right Turn 146.6s / F (PM Peak) Public response 29
TRAFFIC VOLUMES Photo taken by jyoh Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 AM / PM Peak Hours Total Intersection Volume Source Year AM Peak PM Peak Projected IJS 2035 4580 4680 Traffic Count 2011 3924 5644 30
Photo taken by jyoh Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of of Transportation Transportation District 7 District 7 AM / PM Peak Hours Selected Movements Source Year NB Left Turn EB Right Turn Projected IJS (AM) 2035 420 210 Projected IJS (PM) 2035 260 480 Traffic Count (AM) 20112013 577 (687) 318 (376) Traffic Count (PM) 20112013 435 (496) 649 (763) 31
PLANNING HIGHLIGHTS Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Photo courtesy of LJB Eng. 32 P & N Access to regional area Congestion relief / adjoining interchange Economic Development Project CFI New Interchange on I-75 Not Fixing existing Problem Using traffic projections / design OSIP Imagery N
Construction Awarded Feb. 2009 Completion Aug. 2010 Photo courtesy of D-7 PIO Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Consultants: Prime LJB Inc. Sub (Design of CFI) ABMB Engineers Inc. Several other consulting firms involved in planning & design Contractors: Prime John R Jurgenson Company Sub Contractors Traffic Signals Bansal Construction Traffic Signs M P Dory Co. Over 20 sub-contractors in total 33 Bid Information Eight bids in total Range between 22 million and 27.6 million Awarded bid= John R Jurgenson Company $22,005,676.51
ECONOMIC IMPACT: AUSTIN LANDING Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Photo courtesy of LJB Eng. 34 Phase 1 (NE Tract) will include: 500,000 sq. ft. retail, restaurants, entertainment 500,000 sq. ft. professional office 100,000 sq. ft. hospitality 200+ residential units Development Status: First 4-story office building complete & occupied Teradata Corp. has moved into its own 2-story building 87,000 sq. ft. Kohls opened in September 2011 125-room Hilton Garden Inn Kroger Photo from austinlanding.com
DEVELOPMENT Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Photo courtesy of LJB Eng. 35
LESSONS LEARNED Access Management Plan is essential Economic Development (Known/ Unknown) : Future land use plan 20 year traffic-models / Adjoining project effects Public perception (not fixing a known problem) Increase size of signs 36 Ongoing studies: Actual Impacts vs. Projected
PROPOSED CHANGES Continuous Flow Intersection Austin Boulevard & SR 741 Montgomery County, Ohio Ohio Dep t of Transportation District 7 Photo taken by jyoh Sale Date July 2016 Est. Construction End Date June 2017 37
SR 4 BYPASS SUPERSTREETS SUPERSTREET INTERSECTIONS ALLOW FULL MOVMENTS (LEFT, THRU, AND RIGHT TURNS) ON THE MAJOR STREET. TRAFFIC ON THE SIDE STREETS AT THE MAIN INTERSECTION ARE ONLY ALLOWED TO TURN RIGHT ONTO THE MAJOR STREET. PREVIOUS THRU OR LEFT TURN MOVEMENTS FROM THE SIDE STREETS ARE NOW MADE BY MAKING A U-TURN MOVEMENT AT A SIGNALIZED INTERSECTION OR LOON APPROXIMATELY 1000 FEET FROM THE MAIN INTERSECTION.
SR 4 BYPASS SUPERSTREETS
SR 4 BYPASS SUPERSTREETS
SR 4 BYPASS SUPERSTREETS How do we get from here To this?
SR 4 BYPASS SUPERSTREETS 1. ISSUES: 1. THE BYPASS WAS A HIGH SPEED 2 LANE HIGHWAY WITH AVERAGE DAILY TRAFFIC (ADT) VOLUMES OF 20,000-30,000 AS A HIGH COMMUTER ROUTE. 2. HEAVY SIDE STREET TRAFFIC AS WELL FROM SYMMES RD, TYLERSVILLE RD, AND HAMILTON-MASON RD. 3. HIGH NUMBER OF ACCIDENTS OCCURING ALONG THE BYPASS AND AT THE INTERSECTIONS. 4. TYPICALLY CYCLE LENGTHS OF 150-180 SECONDS, WHICH IS VERY HIGH FOR A CONVENTIONAL INTERSECTION. RULE OF THUMB: LONGER CYCLE LENGTHS=LONGER QUEUES. 5. LONGER QUEUES ON A HIGH SPEED ROADWAY MEANS POTENTIAL FOR SEVERE READ- END ACCIDENTS.
SR 4 BYPASS SUPERSTREETS PREVIOUS SAFETY CONDITIONS: 2006-2008
SR 4 BYPASS SUPERSTREET SOLUTIONS? CONVENTIONAL CONCEPTS: SIMPLY WIDENING TO ADD MORE THROUGH LANES AND TURN LANES DOESN T RESOLVE THE POTENTIAL FOR ANGLE AND LEFT TURN CRASHES ON A HIGHSPEED ROADWAY. (IMAGINE SR 32 AT GLEN ESTE-WITHAMSVILLE RD.) CONSTRUCTING INTERCHANGES WOULD TAKE SEVERAL YEARS OF PLANNING AND CONSTRUCTION, CONSIDERABLE RIGHT-OF-WAY ACQUISTION, AND A COST OF TENS OF MILLIIONS OF DOLLARS PER INTERCHANGE.
SR 4 BYPASS SUPERSTREET ALERNATIVE SOLUTION: THE BYPASS WAS WIDENING FROM 2 LANES TO 4 AND 6 LANE SECTIONS FROM SYMMES RD TO SR 129, WHICH WAS NECESSARY IN ANY OF THE PROJECTS. 3 SUPERSTREET INTERSECTIONS WERE CONSTRUCTED AT SYMMES RD, TYLERSVILLE RD, AND HAMILTON-MASON RD TO INCREASE CAPACITY (REDUCES QUEUES) AND REDUCE THE NUMBER OF CONFLICT POINTS (REDUCES SEVERE CONFLICTS). TOTAL OF 3 PROJECTS TO WIDEN 3.25 MILES OF HIGHWAY AND CONSTRUCT THE SUPERSTREETS WAS NEARLY $22.5 MILLION. CONSTRCUTION OF 3 INTERCHANGES WOULD HAVE ADDED TENS OF MILLIONS AND REQUIRED MORE RIGHT-OF-WAY ON THE SIDE STREETS INCLUDING TOTAL TAKES.
SR 4 BYPASS SUPERSTREET IMPROVED SAFETY: REDUCED NUMBER OF CONFLICT POINT: 32 CONFLICT POINTS (16 CROSSING) 14 CONFLICT POINTS (2 CROSSING)
LESSONS LEARNED DESIGN: SUPERSTREETS AREN T IDEAL CANDIDATES FOR LOCATIONS WITH HIGH PEDESTRIAN USAGE. NO PEDS AT HAMILTON-MASON RD, SO COMPLEX OR UNUSUAL PED CROSSINGS HAVE BEEN AVOIDED. ILLUSTRATED CROSSING PATH:
LESSONS LEARNED DESIGN: YOU WON T BE ABLE TO ANTICIPATE AND AVOID ALL POTENTIAL HICCUPS, SO EXPECT TO MAKE CHANGES AFTER OPENED TO TRAFFIC. THERE WILL BE TWEAKS TO THE TRAFFIC CONTROL: ISSUE OF LEFT TURN ON RED BETWEEN TWO ONE-WAY STREETS ALLOWED PER THE OHIO REVISED CODE, BUT SIGNED NOW TURN ON RED AT LOON INTERSECTIONS. PROHIBITED DUE TO HIGH-SPEED CONFLICTS. ADDED PAVEMENT MARKINGS TO IDENTIFY U-TURN AND RIGHT TURN ONLY LANES. VIDEO CAMERA RADAR DETECTION HAD TO BE RAISED TO DETECT FURTHER DOWN THE U- TURN LANES- SHOULD HAVE USED STANDARD LOOP DETECTORS.
LESSONS LEARNED DESIGN: CAREFULLY ON WHAT YOU PROMISE TO THE PUBLIC. ODOT MADE AN ENVIRONMENTAL COMMENT THAT THE LEFT TURN TRAFFIC ON HAMILTON-MASON WOULD GET A GREEN WHEN THEY ARRIVED AT THE LOON INTERSECTION. WHILE WE TIMED THAT THE AMOUNT OF TIME TO TURN RIGHT, MAKE A U TURN, AND RETURN TO THE MAIN INTERSECTION IS THE SAME AS THE TYPICAL WAIT IT USED TO MAKE A LEFT AT THE OLD INTERSECTION-PROMISE MET, BUT IT DOESN T MAKE IT DIFFICULT TO COORDINATE TRAFFIC TRAVELLING STRAIGHT THRU ON THE BYPASS. HOW LONG DO WE KEEP THIS COMMITMENT IF IT S A THE SACFRICE OF A LONGER VOLUME OF TRAFFIC MAKING MORE STOPS.
LESSONS LEARNED DESIGN: NUMBER OF SIGNALIZED INTERSECTIONS: TRY TO CREATE SIGNALIZED INTERSECTIONS THAT USE YOUR STANDARD CABINETS AND CONTROLLERS AND THAT CAN BE MAINTAINED EASILY WITH MAINTENANCE CREWS. CONSIDERED ONE CONTROLLER TO OPERATE ALL THREE INTERSECTIONS, BUT SETUP WOULD BE COMPLEX FOR SIGNAL ELECTRICIANS. DECIDED ON 3 CONTROLLERS 1 PER INTERSECTION USING STANDARD EQUIPMENT AND EASY TO MAINTAIN. IN HIND SIGHT: SHOULD HAVE USED 4 CONTROLLERS AND CABINETS-PER LOON AND 2 AT THE MAIN INTERSECTION. VASTLY DIFFERENT THINKING THAT EACH DIRECTION OF BYPASS CAN BE TIMED INDEPENDENTLY. MAYBE A FUTURE CHANGE???
LESSONS LEARNED CONSTRUCTION: FIRST IMPRESSIONS ARE MOST IMPORTANT: MAKE SURE THAT THE SIGNALS ARE 100% OPERATIONAL INCLUDING DETECTION AND SIGNAL TIMING AT THE TIME OF TURN ON! COMPLAINTS WILL START COMING IN!
LESSONS LEARNED MAINTENANCE: 3 SIGNALIZAED INTERSECTIONS PER SUPERSTREET TO ADD TO MAINTENANCE PROGRAM. AT LEAST 4 OVERHEAD CANTILEVER SIGN SUPPORTS TO ADD TO MAINTENANCE PROGRAM. CENTER INTERSECTION HAS A LARGE TRUSS SIGNAL SUPPORT TO MAINTAIN AS WELL. HOW TO MAINTAIN AND POSSIBLY REPLACE A SUPPORT OVER 200 FEET LONG???
LESSONS LEARNED TYPICAL CUSTOMER FEEDBACK: WHY DO WE HAVE TO STOP AT THE LOON INTERSECTION WHEN THERE ARE NO CARS MAKING U-TURNS. RESULT OF VIDEO DETECTION-SOON TO BE REPLACED WITH RADAR. WHEN TRAVELING STRAIGHT THRU THE LOON AND THE MAIN INTERSECTION, WHY DO I GET STOPPED. A PRODUCT OF ENVIRONMENTAL COMMITMENT TO COORDINATE THE RIGHT TURN FROM SIDE STREET TO GET A GREEN AT THE U-TURN. TWO COMPETING STRATEGIES. HARD TO BALANCE AND TO EXPLAIN! WHY CAN T I TRAVEL THROUGH SYMMES, TYLERSVILLE, AND HAMILTON-MASON RD WITHOUT STOPPING? PRODUCT OF SIGNAL SPACING OF 1.1 AND 1.3 MILES, WHICH IS HARD TO KEEP PLATOON TOGETHER AND COORDINATE FROM SIGNAL TO SIGNAL.
WOULD WE DO IT ALL OVER AGAIN? IMPROVED SAFETY. DEFINITELY! 257 TOTAL ACCIDENTS IN 3 YEARS PRIOR TO SUPERSTREETS, BUT 236 IN 3 YEARS SINCE THEY OPENED TO TRAFFIC. PROPERTY DAMAGE ONLY CRASHES-STAYED THE SAME. 20% REDUCTION IN INJURY CRASHES AND REAR-END CRASHES. NO FATALS. MOVING A HIGH VOLUME OF TRAFFIC. PROBABLY WILL STILL BE WAITING ON THE CONSTRUCTION OF INTERCHANGES.
SR-161 & SUNBURY ROAD SPUI
SR-161 & SUNBURY ROAD SPUI
SR-161 & SUNBURY ROAD SPUI CURRENT DECEMBER 2004
SR-161 & SUNBURY ROAD SPUI SPUI INTERCHANGE IS AN ALTERNATIVE TO A TYPICAL DIAMOND INTERCHANGE. DIAMOND INTERCHANGES TYPICALLY HAVE TWO CLOSE-SPACED SIGNALIZED INTERSECTIONS, WHERE CONGESTION OCCURS BETWEEN THE INTERSECTIONS THAT CAN BLOCK THE INTERSTATE RAMPS. THE TWO SIGNALIZED INTERSECTIONS ARE REPLACED WITH ONE SIGNALIZED INTERSECTIONS AND ALL 4 INTERSTATE RAMPS ARE CURVED TO CREATE A 4 LEGGED, 6 PHASE INTERSECTION AND RAMPS ARE ADDED, TYPICALLY, FOR CONTINUOUS FLOW RIGHT TURN MOVEMENTS.
CHALLENGES SR-161 & SUNBURY ROAD SPUI CLOSELY SPACED INTERCHANGES HIGH TRAFFIC VOLUMES ACCOMMODATE ALL TRAFFIC MOVEMENTS DESIGN WAS VERY COMPLEX WALLS & STRUCTURES WITH VARIOUS TRAFFIC SUPPORTS BUILT AS PART OF A $115M DOUBLE INTERCHANGE PROJECT COMPLETED IN 2007 THE SPUI ELIMINATED AN INTERSECTION/SIGNAL WITHIN THE COORIDOR MET PROJECT GOALS OF INCREASED CAPACITY AND SAFETY
LESSONS LEARNED AFTER 9 YEARS IN OPERATION CONSTRUCTION AND MAINTENANCE OF TRAFFIC WAS CHALLENGING OPERATIONS LARGEST CHALLENGE IS SIGNAL COORDINATION CD ROAD SIGNALS ARE CLOSE TO THE SPUI INTERSECTION MINOR CHANGES SINCE OPENING NB DUAL LEFT-TURN WAS LENGTHENED IN 2011 SPUI DOES NOT INCLUDE ANY PEDESTRIAN FEATURES OVERALL DESIGN IS NOT CONDUCIVE TO PEDESTRIAN ACCESS PEDESTRIAN ACCESS IS PERMITTED ONLY ON ONE LEG AT EACH CD ROAD INTERSECTION OVERALL, CONGESTION AT THE SPUI IS MINOR CD ROAD TRAFFIC FREQUENTLY BACKS UP ESPECIALLY EB
IR-270 & SAWMILL SPUI
IR-71 & SR-665 SPUI
QUESTIONS??