CITY ENGINEERS ASSOCIATION OF MINNESOTA MUNICIPAL ENGINEERING DESIGN STANDARDS THE HOWS AND WHYS OF CITY ENGINEERING DESIGN STANDARDS

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1 CITY ENGINEERS ASSOCIATION OF MINNESOTA MUNICIPAL ENGINEERING DESIGN STANDARDS THE HOWS AND WHYS OF CITY ENGINEERING DESIGN STANDARDS

2 INTRODUCTIONS LARRY POPPLER ASSISTANT CITY ENGINEER CITY OF PRIOR LAKE BRUCE LONEY PUBLIC WORKS DIRECTOR CITY OF SHAKOPEE

3 QUOTES WE RE FOLLOWING THE STANDARD! (TRANSLATION THIS IS HOW WE HAVE ALWAYS DONE THINGS) THE NICE THING ABOUT STANDARDS IS THAT THERE ARE SO MANY TO CHOOSE FROM I VE UPPED MY STANDARDS. NOW UP YOURS. - PAT PAULSON

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5 SPECIAL THANKS TO SURVEY RESPONDANTS BOLTON & MENK ROCKFORD CENTERVILLE OWATONNA BLAINE SPRING PARK SOUTH ST PAUL SHOREVIEW SAVAGE CRYSTAL BIG LAKE ST FRANCIS ANDOVER ST MICHAEL INVER GROVE HEIGHTS RIVER FALLS MINNETONKA WORTHINGTON WILLMAR BLOOMINGTON WASECA ST PETER APPLE VALLEY ELK RIVER OTSEGO MNDOT YAGGY COLBY SHAKOPEE PRIOR LAKE FOR COMPLETE SURVEY RESULTS PLEASE LARRY POPPLER - lpoppler@cityofpriorlake.com

6 WHY HAVE DESIGN STANDARDS? MAINTENANCE PURPOSES CITIZEN EXPECTATIONS SO DEVELOPERS UNDERSTAND CITY EXPECTATIONS UP FRONT UNIFORMITY DURABILITY PERFORMANCE

7 WHY DO DESIGN STANDARDS CHANGE? TECHNOLOGY POLITICAL PRESSURES LEGAL ISSUES SAFETY DEVELOPMENT PRESSURES OTHER GOVERNMENT MANDATES

8 ROADWAY WIDTH 19 OF 24 RESPONDANTS HAVE STANDARD STREET WIDTHS BETWEEN 28 FEET 33 FEET CONSIDERATIONS REDUCED WIDTHS FOR LOW VOLUME ROADS IN NATURAL AREAS OR TO REDUCE RUNOFF REDUCED WIDTHS TO REDUCE UP FRONT COST AND MAINTENANCE COSTS SNOW CAN FURTHER RESTRICT WINTER ROADWAY WIDTHS PRIVATE STREET WIDTHS OR PUDS ON STREET PARKING TRAFFIC CALMING HOW HAVE ROADWAY WIDTHS CHANGED OVER THE YEARS? 28 FOOT LOCAL STREET

9 ROADWAY WIDTH HISTORY TURNING MOVEMENTS OF OXEN TEAMS AND COVERED WAGONS HELPED IN DETERMINING EARLY STREET WIDTHS COLLECTOR STREETS NOT DEFINED IN EARLY STAGES OF ROADWAY PLANNING SHAKOPEE STANDARD STREET WIDTHS HAVE CHANGED OVER THE YEARS FROM 44 FEET TO 40 FEET AND NOW CURRENTLY 36 FEET WITH SPECIAL CONSIDERATIONS IN ENVIRONMENTAL AREAS

10 ROADWAY WIDTH EXAMPLE SHAKOPEE EXAMPLE FOR RESIDENTIAL STREETS 32 FEET WITH SIDEWALK ON ONE SIDE AND NO PARKING ON THE MAILBOX SIDE

11 ROADWAY SECTION MOST CITIES IN THE SURVEY USE 3.5 TO 4 OF BITUMINOUS PLACED IN TWO LIFTS AGGREGATE BASE RANGED FROM 6 TO 10 FOR LOCAL STREETS BASED ON THE SURVEY RESULTS ROUGHLY HALF RESPONDED THAT THEY USE A GRANULAR MATERIAL UNDER THE CLASS V TWO RESPONDANTS INDICATED THAT THEY REQUIRE A 9 TON DESIGN THE LOCAL STREETS RATHER THAN THE TYPICAL 7 TON DESIGN CONSIDERATIONS SOIL CONDITIONS FABRIC, GRID, OR DRAINTILE CHANGES TO SECTIONS OVER TIME EXAMPLE PRIOR LAKE CHANGE TO INCORPORATE 2 FOOT OF GRANULAR SUBGRADE DRAIN TILE ADDED TO GRANULAR BASE TO REMOVE WATER FROM GRANULAR SECTION

12 ROADWAY CROWN 18 OF 26 RESPONDANTS HAD A MINIMUM CROWN OF 2% CONSIDERATIONS CROWN SETTLEMENT OR CROWN NOT BUILT TO PROPER SLOPE IN THE FIELD SOILS FUTURE EDGE MILL AND OVERLAY DRIVEWAY NAVIGATION STANDARD HAS REMAINED CONSISTENT OVER THE YEARS

13 CLASS V MATERIALS 14 OF 25 RESPONDANTS USE MNDOT CLASS 5, 9 OF 25 REQUIRE CRUSHED LIMESTONE, 2 OF 25 USE RECYCLED MATERIAL CONSIDERATIONS CRUSHED LIMESTONE ENSURES ANGULAR AGGREGATE, PERFORMS WELL, EASY TO COMPACT, MORE EXPENSIVE IMPORTANT WITH RECYCLE MATERIALS TO HAVE QUALITY CONTROL OF MATERIAL PLACED AGGREGATE AVAILABILITY BASED ON REGION PLAYS A KEY ROLE IN DECISION ON AGGREGATE CHOICE

14 BITUMINOUS MATERIALS 12 OF 21 RESPONDANTS USE MV MIXTURE, 7 RESPONDED USING LV MIXTURE, SOME USE A COMBINATION. TWO USE AN SP MIX DESIGN MNDOT CHANGES OLD 41A MIX SEEMED TO WORK WELL CONSIDERATIONS SUPERPAVE SEEMS TO BE SUPERIOR PRODUCT BUT COSTS MORE PER TON THE COMBINATION OF MATERIALS, AGGREGATE SIZE, OIL TYPE AND AIR VOIDS CAN BE CHANGED BASED ON THE MIX DESIGNATION MNDOT BITUMINOUS ENGINEERING DIVISION CAN HELP YOU DETERMINE THE PROPER MIX DESIGNATION FOR YOUR CITY TRAFFIC VOLUME

15 ROADWAY SLOPES MAXIMUM SLOPES 14 OF 22 RESPONDED THAT THEIR MAXIMUM SLOPE FOR LOCAL STREETS IS 7% OR 8% CONSIDERATIONS TOPOGRAPHICAL CHALLENGES REQUIRE SOME CITIES TO HAVE STEEPER MAXIMUM SLOPES STANDARD TOO STEEP CAN PRESENT MAINTENANCE CHALLENGES IN THE WINTER MINIMUM SLOPES VIRTUALLY ALL RESPONDED WITH A MINIMUM SLOPE OF 0.4%-0.6% CONSIDERATIONS DRAINAGE AT LOW POINTS 19% GRADE STREET

16 CUL DE SAC RADIUS SURVEY RESULTS SHOW EVEN DISTRIBUTION BETWEEN RADIUS STANDARDS FOR CUL-DE-SACS CONSIDERATIONS CHANGES OVER TIME TURNING RADIUS FIRE TRUCKS (PRIOR LAKE LADDER TRUCK 37.5 FT TURNING RADIUS CHECK WITH YOUR FIRE CHIEF OR FIRE CODE) WB-62 (50 FT TURNING RADIUS) SNOW REMOVAL IMPERVIOUS SURFACE PARKING

17 CONCRETE CURB AND GUTTER WHY CONCRETE CURB AND GUTTER? REDUCES PAVEMENT EDGE FAILURE CONTROLS DRAINAGE PREVENTS EROSION - KEEPS WATER OUT OF SUBGRADE IMPROVES APPEARANCE DRIVEWAY AND TRAFFIC CONTROL AIDS IN STREET CLEANING DITCH SECTION REQUIRES MORE RIGHT OF WAY SNOW PLOWING LOW IMPACT DESIGN MOST RESPONDED THAT THEY USE B618 CONCRETE CURB AND GUTTER IN AREAS WHERE THE DRIVEWAYS LOCATIONS ARE SET AND A TYPE OF SURMOUNTABLE CURB AND GUTTER FOR NEW SUBDIVISIONS WHERE THE DRIVEWAY LOCATIONS ARE NOT KNOWN.

18 CONCRETE CURB AND GUTTER CHANGES PRIOR LAKE EXAMPLE INITIALLY CITY TRIED VARIOUS TYPES OF SURMOUNTABLE INCLUDING D412 FOR NEW SUBDIVISIONS AND B618 FOR RECONSTRUCTION NOW USES SURMOUNTABLE FOR NEW SUBDIVISIONS AND B618 FOR RECONSTRUCTION

19 DRIVEWAY SLOPES VAST MAJORITY RESPONDED ON DRIVEWAY SLOPES WITH A MINIMUM SLOPE OF 2% AND A MAXIMUM OF 10% MNDOT MAXIMUM 15% CONSIDERATIONS VEHICLE CLEARANCE DRAINAGE HOMEOWNER PREFERENCES LANDING AREAS PRE-EXISTING CONDITIONS CITIES WITH HILLY TERRAIN RESPONDED WITH STEEPER MAXIMUM DRIVEWAY STANDARDS MOST CHALLENGING ARE DRIVEWAYS ON ROADS PARALLEL TO TERRAIN

20 DRIVEWAY SLOPES CONTINUED CONSIDERATION FOR VEHICLE APPROACH ANGLE, BREAKOVER ANGLE, AND DEPARTURE ANGLE

21 SIDEWALK WIDTH 19 OF 26 RESPONDED WITH 5 FOOT SIDEWALK WIDTH STANDARD CONSIDERATIONS TREND MAY BE TOWARD 6 FOOT SIDEWALK 6 FOOT WIDE ALLOWS TWO WHEELCHAIRS TO PASS EACH OTHER CITY PLOWING EQUIPMENT WIDTH OR PLOWING MARGIN FOR ERROR CONSTRUCTION SKID LOADER WIDTH 5.5 FT OR 6 FT WIDTH THICKNESS MOST RESPONED THAT 4 CONCRETE IS USED WITH 6 USED AT DRIVEWAY LOCATIONS. ALSO MOST RESPONDED THAT THEY USE 6 OF AGGREGATE BASE CONSIDERATIONS NEW DEVELOPMENTS SHOULD CONSIDER USING 6 SINCE DRIVEWAY LOCATIONS NOT DETERMINED AND HOUSING CONSTRUCTION DAMAGE VERTICAL LIFT DUE TO ROOTS

22 BITUMINOUS TRAIL WIDTH SEVERAL RESPONDANTS USE 10 FT ALL OTHERS RESPONDED THAT THEY USE 8 FT CONSIDERATIONS 8 FOOT STANDARD PAVER WIDTH 10 FOOT WIDTH ON COUNTY ROADS OR STATE HIGHWAYS THICKNESS MOST RESPONDED THAT THEY SPECIFY 2.5 OR 3 THICK PAVEMENT WITH 6 OF CLASS 5 AGGREGATE BASE CONSIDERATIONS INCREASED THICKNESS MAY BE NECESSARY IF TRAIL IS ALSO USED AS A MAINTENANCE OR EMERGENCY ROUTE

23 GRADING MAXIMUM GRADES MAINTAINED AREAS - 17 OF 23 RESPONDANTS REPLIED THAT 4:1 SLOPE WAS THE MAXIMUM ALLOWED REMAINING RESPONDANTS REPLIED WITH 3:1 MAXIMUM SLOPE NON-MAINTAINED AREAS MOST RESPONDED THAT 3:1 SLOPE WAS THE MAXIMUM ALLOWED MINIMUM GRADES MAINTAINED AREAS RESPONDANTS SPLIT EVENLY BETWEEN 2% AND 1% CONSIDERATIONS BACKYARD LANDING AREAS ELIMINATE FALL OUTS DRAINAGE SWALES < 2% CAN BE PROBLEMATIC DUE TO TOLERANCE LEVELS OF HOUSING CONTRACTORS YARD SETTLEMENTS NEAR THE HOME CAN CAUSE DRAINAGE BACKFLOWING TOWARD FOUNDATION

24 STORM SEWER PIPE PIPE MATERIALS NEARLY ALL RESPONDANTS STILL USE RCP UNDER ROADWAYS WITH HDPE OR PVC USED IN GREEN AREAS MINIMUM PIPE SIZE 17 OF 25 RESPONDED WITH A MINIMUM PIPE SIZE OF 12 INCHES CONSIDERATIONS HDPE PIPE BEDDING RCP HAS LASTED THE TEST OF TIME CLEANING AND MAINTENANCE LOW COST TO UPGRADE SIZE

25 STORM SEWER CATCHBASINS HISTORICAL CHANGES INTAKE CAPACITY SAFETY (BIKE SAFE) OUTDATED GRATES CURRENT STANDARD VANE GRATE

26 STORM SEWER MINIMUM SLOPE VARIABLE STANDARDS MOST POPULAR WERE 3 FPS STANDARD OR 0.5% MINIMUM SLOPE STORM SEWER DESIGN EVENT 21 OF 26 REPONDED THAT THEY DESIGN FOR THE 10 YEAR STORM EVENT. FOUR RESPONDED THAT THEY USE THE 5 YEAR STORM EVENT CONSIDERATIONS PIPE SETTLEMENT OR PIPE CONSTRUCTED LESS THAN THE MINIMUM ON STREET PONDING

27 WATERMAIN PIPE MATERIALS MAJORITY OF RESPONDANTS USE DIP AS THEIR STANDARD. SOME ALLOW PVC, C900, OR HDPE PIPE MATERIALS CHANGES OVER TIME WOOD, CAST IRON SERVICE PIPE MATERIALS MOST CITIES STILL USE COPPER SERVICE PIPE BUT PVC OR HDPE MAY BECOME MORE PREVALENT IN THE FUTURE WOOD WATERMAIN

28 WATERMAIN PIPE SIZE 17 OF 27 RESPONDED THAT 8 WAS THEIR MINIMUM STANDARD. ALL OTHERS RESPONDED WITH 6 SERVICE PIPE SIZE ALMOST ALL RESPONDED WITH 1 AS THEIR MINIMUM SERVICE SIZE CONSIDERATIONS FIRE FLOW DISTRIBUTION SYSTEM MODEL SMALLER 6 SIZE FOR DEAD END LINES TO REDUCE STAGNANT WATER ISSUES IF SPRINKLER SYSTEMS BECOME STANDARD IN HOUSEHOLDS LARGER SERVICE LINES MAY BE NECESSARY

29 SANITARY SEWER PIPE MATERIALS ALL RESPONDANTS USE PVC PIPE MATERIALS. DEPTH OF PIPE DICTATES MATERIAL TYPE HISTORICAL PERSPECTIVE SHAKOPEE EXAMPLE ORANGEBURG, VCP, CAST IRON, AND CURRENT STANDARD PVC MOST CITIES NOW REQUIRE TELEVISING REPORT

30 SANITARY SEWER MANHOLES HISTORICAL CHANGES INFILTRATION OR DEBRIS THROUGH VENTED LID ACCESS ISSUES IN CONCEALED LID

31 SANITARY SEWER HISTORY EARLY STANDARD LAMPHOLES NOT MANHOLES NO SEALED PIPE JOINTS

32 SANITARY SEWER LOCATING 10 OF 21 USE TRACER WIRE FOR SANITARY SEWER LOCATING OTHER OPTIONS INCLUDE: GPS LOCATING RECORD DRAWINGS MARKER BALL STAMP S IN CURB

33 STANDARDS ARE ALWAYS CHANGING REVIEW YOUR CITY S STANDARDS PERIODICALLY UNDERSTAND BASIS OF STANDARD IF STANDARD DOES NOT WORK, REVIEW OTHER CITIES STANDARD AND CHANGE THE STANDARD OTHER RESOURCES TO CHANGE OR DEVELOP YOUR STANDARD: AASHTO, 10 STATES STANDARDS, MNDOT, AWWA STANDARDS IF YOUR CITY DOES NOT HAVE STANDARDS, CREATE STANDARDS

34 COST EFFECTIVE ALTERNATIVES RICH REVERING BOLTON & MENK

35 QUESTIONS? THANK YOU!