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ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-1 6.0 Intersection Decision Process Building on the travel demand analysis documented in Section 5.0, the intersection decision process focused on identifying intersections that are either currently experiencing congestion, or are projected to experience congestion by 2030. The county applied established criteria related to safety, traffic operations, and facility type to identify and analyze capacity challenged intersections. The results of this process are prioritized lists of intersection improvement recommendations for addressing existing and future capacity issues that have been matched to cost-effective solutions. 6.1 Intersection Improvements Considered In making intersection improvement recommendations to address existing and future capacity issues at intersections identified by this screening process, the county focused on the strategies listed and shown below in Table 6-1. In addition to physical changes, the county considered access management strategies and corridor studies to address congestion and safety problems at intersections. Access management involves “planning, design and implementation of land use and transportation strategies in an effort to maintain a safe flow of traffic while accommodating the access needs of adjacent development.”1 Corridor studies incorporate analysis of multiple intersections along a corridor or within close proximity to one another and development of a customized mix of alternative strategies that best address the needs of the study area. TABLE 6-1 Range of Intersection Improvements Considered Type Example Interchange—A road junction that utilizes grade separation and ramps to permit traffic on at least one road to pass through the junction without crossing any other traffic stream. Typically used on freeways where access is only provided at interchanges. Examples: Diamond interchange (see picture to right), single-point diamond interchange, cloverleaf interchange. 1 Source: Mn/DOT Access Management Policy & Manual, January 2008 ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-2 TABLE 6-1 Range of Intersection Improvements Considered Type Example Grade-Separated Intersection—A road junction that utilizes a grade separation. Typically used on arterials where access is at signalized intersections where some private access is allowed. Examples: Echelon intersection (see picture to the right), center turn overpass, diverging diamond. Source: Applied Technology and Traffic Analysis Program Web site (Office of Traffic and Safety at the Maryland State Highway Administration and the Traffic Safety and Operations Laboratory at the University of Maryland–College Park). Roundabout—An intersection at which traffic enters a one- way, counter-clockwise stream around a circular, central island, with yield control of all entering traffic. Signalized Intersection—Use of traffic signals to indicate turning right-of-way. ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-3 6.2 Intersection Decision Process and Results Summary The strategies shown in Table 6-1 are solutions to several, but not all intersection capacity problems. Figure 6-1 shows the association between the traffic volumes and recommended intersection improvement strategies. An interchange is only appropriate when the traffic volumes are over 50,000 total vehicles per day (vpd) (40,000 on the major roadway and at least 10,000 vehicles on the minor roadway). Also, single-lane roundabouts are only appropriate when the total volume is less than 20,000 vpd. FIGURE 6-1 Appropriate Intersection Improvement Strategy based on Traffic Volume Criteria The Intersection Decision Process used traffic volumes, intersection safety/crash data, facility type, and other criteria to determine the appropriate strategy for intersection improvements. An overview of this process is provided in Figure 6-2. The countywide review of all intersections resulted in a list of recommended future projects that when implemented, will improve traffic operations and safety. These recommendations are shown in Figure 6-3. The rest of the section documents the intersection decision process and the results for specific types of improvement alternatives. ---PAGE BREAK--- Figure 6-2 Overview: Intersection Decision Process ANOKA COUNTY 2030 TRANSPORTATION PLAN Source: Anoka County’s Intersection Decision Analysis (CH2M HILL, 2008) ---PAGE BREAK--- $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ " " " " " " " " " " ! ! ! # ! # # # # # # # # # # ! ! ! # # ! : 74 : 81 : 140 : 73 : 64 : 85 : 102 : 103 : 79 : 132 : 84 : 76 : 116 : 57 : 58 : 16 : 15 : 68 : 18 : 87 : 61 : 56 : 27 : 60 : 82 : 71 : 72 : 163 : 67 : 62 : 66 : 63 : 70 : 65 : 86 : 77 : 75 : 53 : 89 31 11 49 6 5 32 51 17 10 1 13 8 14 78 52 17 9 7 23 20 2 14 34 9 22 1 18 23 24 28 19 12 54 83 35 116 78 26 21 36 22 24 22 35W Nowthen Oak Grove East Bethel Linwood Columbus Ham Lake Andover Ramsey Blaine Coon Rapids Anoka Centerville Fridley Columbia Heights St. Francis 694 35W 35E 35 Hilltop Lexington Circle Pines Lino Lakes Hennepin County Wright County Sherburne County Chisago County Washington County L AKE DR CROS STO W N BLVD NE LAKE DR NE MAIN ST LEXINGTON AVE NE VIKING BLVD NW 237TH AVE N W ELM ST R U M RIVER BLVD N W BUNKER LAKE BL VD N W KE T T LE RIV E R BL V D NE BROADWAY AVE NE 109TH AVE NE RADISSON RD NE MAIN ST 221ST AVE NE 181ST AVE NW VERDIN ST NW MAIN ST NW 229TH AVE NW BIRCH S T 237T H AV E NE CONSTANCE BLVD NE DURAN T ST NE ASH ST 125TH AVE NE VIKING BLVD NE 229TH AVE NE F O LE Y BL V D NW UNIVERSITY AVE NE AMBASSADOR B L V D NW A R MST RONG BLVD NW 7TH AVE NW C LEAR Y RD NW CEDAR DR NW POTOMAC ST NE LAKE GE O R GE BLV D N W BAUGH ST NW É 47 É 47 É 65 É 65 É 47 É 610 Figure 6-3 ANOKA COUNTY 2030 TRANSPORTATION PLAN ± 1 inch = 3 miles 0 3 6 1.5 Miles Last Updated: 08/04/2009 Intersection Improvements Æÿ Local Roads Interstates US Highways State Highways County State Aid Highways (CSAH) County Roads £ ¤ Æÿ Legend # Grade-Separated Intersection ! New Interchange " Upgrade Existing Interchange New Signal Locations $ High Probability of Meeting Warrants $ Moderate Probability of Meeting Warrants segments Source: Anoka County's Intersection Decision Analysis (CH2M HILL, 2008) )m )m )m + ¡ ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-6 6.3 Interchanges/Grade-Separated Intersection Process Summary and Results 6.3.1 Interchange and Grade Separation Process The process and criteria used to determine the need for new and upgraded interchanges and grade separations is summarized in Figure 6-4 and described below. 1) Interchange/Grade-Separated Intersection Criterion Traffic Volumes—Using traffic volumes at locations where grade separations have recently been built as a general guideline, the county determined those intersections with average daily traffic (total on both roadways) of greater than 50,000 vpd should be considered for an interchange or a grade-separated intersection. At more than 50,000 vpd, it becomes difficult to coordinate traffic signals while also providing an acceptable level of service (LOS). Locations with more than 50,000 vpd were moved into Criterion Locations that had less than 50,000 vpd were moved to Criterion and were considered for interchanges or grade-separations only if the main roadway is, or is planned to be, a freeway. 2) Interchange/Grade-Separated Intersection Criterion Traffic Operations— This step identified locations with operational issues at existing interchanges or it was anticipated to have future operational issues based on projected traffic volumes. These locations were automatically recommended for interchange upgrade improvements (see Table 6-2). Locations that met Criterion #1 (more than 50,000 vpd at the intersection) but did not have an existing interchange, were moved to Criterion TABLE 6-2 Interchange Upgrade Locations by Intersection 1. CSAH 10 & TH 47/University Ave. 6. I-35 & CSAH 23/Lake Dr. 2. CSAH 10 & TH 65/Central Ave. 7. I-35W & CSAH 17/Lexington Ave. 3. US 10 & US 169/TH 47/Ferry St. 8. I-35W & CSAH 23/Lake Dr. South 4. US 10 & CSAH 7/7th Ave. 9. I-35W & CSAH 23/Lake Dr. North 5. I-35E & CSAH 14/Main St. Note: The intersection at US 10 and West Main St. in Anoka met Criterion however, was removed from the list because of the proximity to the interchanges at US 10 and US 169/TH 47/Ferry St. and to US 10 and CSAH 7/7th Ave. ---PAGE BREAK--- Figure 6-4 Interchange/Grade-Separation Decision Process Flow Chart ANOKA COUNTY 2030 TRANSPORTATION PLAN Criteria #1 Criteria #1 Traffic Volumes Traffic Volumes No Solution Necessary or Needs Another Screening Process Criteria #2 Criteria #2 Traffic Operations Traffic Operations Less than 50,000 veh/day through intersection More than 50,000 veh/day through intersection Existing interchange WITHOUT congestion Existing interchange WITH congestion Upgrade Interchange Criteria #3 Criteria #3 Facility Type Facility Type Not an existing interchange Future Freeway Facility New Interchange Arterial Roadway Criteria #4 Criteria #4 Facility Type Facility Type New Grade- Separation Needed for Consistency of Corridor Not Needed for Consistency of Corridor Source: Anoka County’s Intersection Decision Analysis (CH2M HILL, 2008) ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-8 3) Interchange/Grade-Separated Intersection Criterion Facility Type (freeway or non- freeway)—Criterion #3 considered the future main roadway type (freeway, arterial, or conventional roadway) or intersections. Interchanges are only appropriate on freeways, while grade-separated intersections are usually considered appropriate for signalized arterials or conventional roadways. Generally, interchanges are not placed on signalized arterials because an interchange on a signalized corridor would not meet driver expectations. The list of new interchange locations is provided in Table 6-3; future grade- separated intersections are in Table 6-4. TABLE 6-3 New Interchange Locations by Intersection 1. US 10 & CSAH Blvd. 5. TH 65 & CSAH 116/Bunker Lake Blvd. 2. US 10 & CSAH 57/Sunfish Lake Blvd. 6. TH 65 & CSAH 14/Main St./125th Ave. NE 3. US 10 & Thurston Ave. 7. TH 65 & CSAH 12/109th Ave. 4. US 10 & CSAH 56/Ramsey Blvd. TABLE 6-4 New Grade-Separated Intersection Locations 1. US 169 & MSA 143/Main St. 2. CSAH 116/Bunker Lake Blvd. & CSAH 78/Hanson Blvd. 3. CSAH 78/Hanson Blvd. & CSAH 14/Main St. 4. CSAH 116/Bunker Lake Blvd. & CSAH 9/Round Lake Blvd. 5. CSAH 51/University Ave. & CSAH 12/Northdale Blvd./109th 6. TH 65 & CSAH 8/Osborne Road 7. CSAH 1/East River Road & CSAH 6/Mississippi St. 8. TH 47/University Ave. & CSAH 6/Mississippi St. 9. TH 47/University Ave. & CSAH 8/Osborne Road 10. CSAH 17/Lexington Ave. & CSAH 23/Lake Dr. 11. CSAH 17/Lexington Ave. & CSAH 14/Main St. ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-9 3) Interchange/Grade-Separated Intersection Criterion Facility Type (Consistency)—Criterion #4 is for the small number of locations that have the potential need to be upgraded based on consistency with roadway type (the rest of the intersections along the roadway are to be upgraded to an interchange and the main roadway will become a freeway), and not because of future volume needs. The four TH 65 county road intersections north of CSAH 116/Bunker Lake Boulevard (listed in Table 6-5) should be considered for grade-separated intersections or interchanges. Even though traffic volumes for this area of TH 65 are projected to be less than 50,000 vpd, grade-separated intersections or interchanges are recommended based on the planned upgrade of this segment of TH 65 to a freeway, including an interchange at CSAH 116/Bunker Lake Boulevard. 6.4 Roundabout/Corridor Study Process Summary and Results The process used to consider roundabouts as a potential solution to address intersection capacity issues is summarized in Figure 6-5 and described below. From this analysis, locations that would benefit from a Corridor Study were also determined and are listed in Table 6-6. A detailed listing of the locations and screening for Roundabouts and Corridor Studies can be found in Appendix E, Roundabout Decision Process Screening Summary. Roundabout/Corridor Study Criterion High-Incident Crash Locations—The county identified 51 locations on county roadways that experienced more than 25 crashes in a five year period (2002–2006). Guidelines indicate that these high-incident crash locations would experience a crash reduction benefit through implementation of a roundabout.2 High- incident crash locations were moved forward to Criterion Roundabout/Corridor Study Criterion Corridor/Area Studies in Select Locations— Corridor or area studies were recommended for roadways with multiple high-incident crash locations, especially if the problem crash locations were in close proximity to one another. The corridors, listed in Table 6-6, include 27 of the 51 locations discussed above. Corridor/area studies will determine any correlation between the high-incident crash locations and include a review to determine an appropriate improvement plan, which may include roundabouts. 2 Source: MnMUTCD, May 2005, Chapter 4C.8, Warrant 7, Crash Experience. TABLE 6-5 New Grade-Separated Intersection/Interchange Locations TH 65 & CSAH 22/Viking Blvd. TH 65 & CSAH 18/Crosstown Blvd. TH 65 & CR 60/Constance Blvd. TH 65 & CR 16/Andover Blvd. ---PAGE BREAK--- Figure 6-5 Roundabout/Corridor Study Decision Process Flow Chart ANOKA COUNTY 2030 TRANSPORTATION PLAN Screen #1 Screen #1 High Incident High Incident Crash Location Crash Location No Solution Necessary or Needs Another Screening Process Screen #2 Screen #2 Corridor Study Needed Corridor Study Needed Less than 5 crashes per year More than 5 crashes per year Multiple High Incident Locations along one corridor Corridor Study Screen #3 Screen #3 Traffic Volumes Traffic Volumes Not related to other high incident locations More than 20,000 vehicles per day New or Improved Signal or Access Management (see Intersection Screening) Less than 20,000 vehicles per day Screen #4 Screen #4 Crash Characteristics Crash Characteristics Less than 40% angle crashes Screen #5 Screen #5 Facility Type Facility Type More than 40% angle crashes Roundabout Part of existing coordinated signal network NOT part of existing coordinated signal network Source: Anoka County’s Intersection Decision Analysis (CH2M HILL, 2008) ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-11 TABLE 6-6 Recommended Corridor and Area Study Locations Roadway Extent CSAH 17/Lexington Ave. and CSAH 23/Lake Dr. See East-Central Sub-area on Figure 5-1 and discussion and graphics in Section 7.0 CSAH 24/Bridge St. See St. Francis Sub-area on Figure 5-1 and discussion and graphics in Section 7.0 CSAH 51 Area Study Extension to CSAH 13 CSAH 1/Coon Rapids Blvd. CSAH 7/7th Ave. to TH 610 (CSAH 1 Corridor Study to begin in early 2009) CSAH 1/East River Rd. Corridor Study CR 3 to I-694 CSAH 9 and CSAH 14/Main St to CSAH 20/157th St. See West-Central Sub-area on Figure 5-1 and discussion and graphics in Section 7.0 CSAH 10 Corridor Study TH 47 to County Line CSAH 11/Foley Blvd. Corridor Study CSAH 1 to CSAH 12/Northdale Blvd. Twenty-four of the 51 high-incident crash intersections were located on a corridor that did not have a concentration of other high-incident crash intersections. These locations were moved into Criterion Roundabout/Corridor Study Criterion Impact of Traffic Volumes on High-Incident Crash Locations—Locations with more than 20,000 vpd would meet standards for needing a signal, and require a multi-lane roundabout to accommodate capacity. The county, at this time, chooses not to implement multiple-lane roundabouts since they are not currently widely implemented within the Twin Cities Metro Area and are not fully tested. Twenty-two of the twenty-four remaining locations that had traffic volumes over 20,000 vpd were moved into the signalized intersection decision process described in Section 6.5. New or improved traffic signal or access management strategies were recommended for intersections with more than 20,000 vpd (see the intersection screening discussion below). A roundabout with one lane in each direction would accommodate traffic volumes of less than 20,000 vpd. Two high-incident crash intersections that also accommodate less than 20,000 vpd were moved forward into Criterion Roundabout/Corridor Study Criterion Crash Characteristics—Intersections where more than 40 percent of the crashes are angle crashes (right angle and left turn) would benefit most from implementation of a roundabout. The expected crash distribution for angle crashes is around 32 percent.3 One location had an angle crash distribution of 58 percent and was moved onto Criterion The other location had 36 percent angle crashes and was moved into the signalized intersection decision process, because a roundabout would not provide a substantial safety benefit. 3 Source: Mn/DOT Office of Traffic, Safety, and Technology, Traffic Fundamental Handbook, August 2008. ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-12 Roundabout/Corridor Study Criterion Facility Type—Generally, roundabouts are not recommended intersection types on roadways with coordinated signal systems because they interfere with the coordination that requires vehicles to arrive at the signal in platoons to maintain efficiency of the system. While this does not preclude a roundabout from being built within a coordinated system of signals, it needs to be carefully considered and modeled before it is implemented. Therefore, roundabouts were only considered for isolated intersections for this exercise but could still be suggested during a Corridor Study. 6.4.1 Roundabout/Corridor Study Results After carrying out the roundabout decision process, no intersections were identified as being optimal for roundabout implementation at isolated locations. This does not preclude any roundabouts from being implemented based on future Corridor Study recommendations (see Table 6-6 for the locations where a Corridor Study was recommended). 6.5 Signalized Intersection Process Summary and Results The process used to consider signalized intersections as a potential solution to address intersection capacity and safety issues is summarized in Figure 6-6 and described below. The selection of new signalized intersection locations was based on existing and forecasted traffic volumes and high crash locations. Signalized Intersection Criterion Traffic Volumes (Main Roadway)—The main roadway of an intersection should have traffic volumes of greater than 10,000 vpd to meet the minimum standard, or warrant for a traffic signal.4 Unsignalized intersections where the main roadway has more than 10,000 vpd were moved into Criterion Signalized Intersection Criterion Traffic Volumes (Cross Roadway)—The roadway crossing a main road (with more than 10,000 vpd) would need to have traffic volumes of at least 3,000 vpd to meet signal warrants.5 Intersections meeting Criterion #1 and Criterion #2 were moved into Criterion Signalized Intersection Criterion Traffic Volumes (Probability of Signal Warrant)— Locations meeting the first two criteria were ranked on probability of meeting signal warrants based on the total amount of traffic (major roadway daily volumes plus the minor roadway volumes). Intersections with more than 22,000 vpd have high probability of meeting signal warrants in the future. Intersections with volumes of 13,000–22,000 vpd have moderate probability of meeting signal warrant.6 4 Source: MnMUTCD, May 2005 and unpublished Mn/DOT Research. Traffic engineers have established minimum conditions, or warrants, to assist in determining the need for a traffic signal at an intersection. Warrants were established to ensure that the advantages outweigh the disadvantages prior to installing a traffic signal, and also to provide consistency with the implementation of traffic signals. Warrants identify the minimum conditions under which a signal should be installed. 5 Source: MnMUTCD, May 2005 and unpublished Mn/DOT Research. 6 Source: MnMUTCD, May 2005. ---PAGE BREAK--- Figure 6-6 Signalized Intersection Decision Process Flow Chart ANOKA COUNTY 2030 TRANSPORTATION PLAN Screen #1 Screen #1 Main Roadway Main Roadway Volume Volume Greater than 10,000 vehicles per day No Improvement Proposed Screen #2 Screen #2 Cross Roadway Cross Roadway Volume Volume New Signal High Probability of Meeting Signal Warrant Less than 10,000 vehicles per day Greater than 3,000 vehicles per day Less than 3,000 vehicles per day Screen #3 Screen #3 Probability of Probability of Signal Warrant Signal Warrant New Signal Moderate Probability of Meeting Signal Warrant Total Intersection ADT less than 22,000 vehicles per day Total Intersection ADT more than 22,000 vehicles per day Screen #4 Screen #4 High Incident High Incident Crash Locations Crash Locations Confirmed that there were no un-signalized high incident crash locations that did not meet a signal warrant based on volumes. Source: Anoka County’s Intersection Decision Analysis (CH2M HILL, 2008) ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-14 Signalized Intersection Criterion High-Incident Crash Locations—After identifying locations that met traffic volume signal warrants, the county reviewed all high-incident intersections (where more than 25 crashes occurred from 2002-2006) to determine if any high crash intersections were not addressed in the previous decision processes (either through interchange/grade-separated intersection, roundabout/corridor study or signalized intersections). The county confirmed that there were no unsignalized, high-incident crash locations that did not meet a signal warrant based on traffic volumes. The process described above resulted in the county recommending that signals be considered at the intersections listed in Table 6-7. Prior to installing signals at any of the intersections listed above, the county will thoroughly evaluate the effectiveness of the signal in addressing intersection deficiencies. 6.6 Next Steps The intersection recommendations made in this section were carried forward into Section 7.0, Evaluation Process and Recommendations, which looks beyond intersections, and documents the results of the county’s efforts to develop and prioritize projects for the entire Anoka County transportation system. Capacity projects considered in Section 7.0 include: Intersection improvements from the lists developed in this section, Widening roadways by adding lanes based on travel demand results summarized in Section 5.0, and Improving the supporting roadway network by making new roadway connections. ---PAGE BREAK--- ANOKA COUNTY 2030 TRANSPORTATION PLAN DECEMBER 2008 6-15 TABLE 6-7 Signalized Intersection Results Road Intersection Warrant Probability Road Intersection Warrant Probability CSAH 116 CR 52 High CSAH 23 CR 19 Moderate CSAH 116 CR 57 High CSAH 24 CR 103 Moderate CSAH 12 CR 53 Moderate CSAH 24 CSAH 26 Moderate CSAH 14 CR 53 High CSAH 24 CSAH 9 High CSAH 14 4th Ave Moderate CSAH 5 CR 163 High CSAH 14 Rondeau Lake Rd Moderate CSAH 5 CR 63 (North) High CSAH 17 CR 60 High CSAH 5 CR 63 (South) Moderate CSAH 17 149th High CSAH 5 CR 57 Moderate CSAH 17 CSAH 116 High CSAH 56 Alpine Dr. Moderate CSAH 18 CR 19 High CSAH 56 CSAH 5 Moderate CSAH 18 CSAH 17 (North) High CSAH 56 167th Ave. Moderate CSAH 18 CSAH 17 (South) High CSAH 58 CR 67 High CSAH 18 CR 68 High CSAH 58 CSAH 78 High CSAH 18 E. Lake Netta Dr High CSAH 7 CR 58 Moderate CSAH 18 CSAH 58 High CSAH 7 147th Ave. High CSAH 18 CSAH 62 Moderate CSAH 78 133rd High CSAH 20 Crosstown Blvd Moderate CSAH 78 CSAH 20 Moderate CSAH 20 University Ave Moderate CSAH 83 161st Ave. Moderate CSAH 22 CSAH 5 High CSAH 83 Alpine Dr. High CSAH 22 TH 47 High CSAH 83 CSAH 116 High CSAH 22 CSAH 7 High CSAH 9 CSAH 58 High CSAH 22 CSAH 9 High CSAH 9 MSA 116/168th Moderate CSAH 22 CSAH 78 High CSAH 9 MSA 108/Coon Creek Dr. High CSAH 22 CR 67 (South) High CR 49 Lever St. High CSAH 22 CR 67 (North) High CR 52 Cloud Dr. Moderate CSAH 22 CR 15 Moderate CR 52 Tournament Players Pkwy Moderate CSAH 22 CR 74 Moderate CR 53 CR 49 Moderate CSAH 22 CSAH 85 High CR 53 105th/Gladstone Moderate CSAH 22 CR 163 High CR 53 CR 153 Moderate CSAH 22 CR 64 Moderate CR 57 Alpine Dr. Moderate CSAH 22 CR 68 Moderate TH 65 CR 74 High CSAH 22 CSAH 17 Moderate