Topic # 625-000-015 DRAFT May - 2012007 Manual of Uniform Minimum Standards Printed 2/73/4/20110 for Design, Construction and Maintenance for Streets and Highways CHAPTER 3 GEOMETRIC DESIGN A INTRODUCTION ............................................................................................... 3-1 B OBJECTIVES ............................................................................................... 3-43-3 C DESIGN ELEMENTS ................................................................................... 3-53-4 C.1 Design Speed ................................................................................. 3-53-4 C.2 Design Vehicles .............................................................................. 3-63-5 C.3 Sight Distance ................................................................................. 3-73-6 C.3.a Stopping Sight Distance .................................................. 3-83-7 C.3.b Passing Sight Distance ................................................... 3-83-7 C.3.c Sight Distance at Decision Points ................................... 3-93-8 C.3.d Intersection Sight Distance ........................................... 3-103-9 C.4 Horizontal Alignment ..................................................................... 3-103-9 C.4.a General Criteria ............................................................. 3-103-9 C.4.b Superelevation ............................................................ 3-113-10 C.4.c Curvature .................................................................... 3-123-11 C.4.d Superelevation Transition (superelevation runoffs plus tangent runoff) ............................................................. 3-133-11 C.4.e Lane Widening on Curves ........................................... 3-133-12 C.5 Vertical Alignment ....................................................................... 3-143-13 C.5.a General Criteria ........................................................... 3-143-13 C.5.b Grades ........................................................................ 3-143-13 C.5.c Vertical Curves ............................................................ 3-153-14 C.6 Alignment Coordination ............................................................... 3-153-14 C.7 Cross Section Elements .............................................................. 3-173-16 C.7.a Number of Lanes ........................................................ 3-173-16 C.7.b Pavement .................................................................... 3-173-16 C.7.b.1 Pavement Width ....................................... 3-173-16 C.7.b.2 Pavement Cross Slope (not in superelevation) .............................. 3-173-16 C.7.c Shoulders .................................................................... 3-183-17 Geometric Design 3-i Topic # 625-000-015 DRAFT May - 2012007 Manual of Uniform Minimum Standards Printed 2/73/4/20110 for Design, Construction and Maintenance for Streets and Highways C.7.c.1 Shoulder Width ......................................... 3-183-17 C.7.c.2 Shoulder Cross Slope .............................. 3-193-18 C.7.d Sidewalks .................................................................... 3-193-18 C.7.e Medians ...................................................................... 3-203-19 C.7.e.1 Type of Median ......................................... 3-223-20 C.7.e.2 Median Width ........................................... 3-233-21 C.7.e.3 Median Slopes .......................................... 3-233-21 C.7.e.4 Median Barriers ........................................ 3-243-22 C.7.f Roadside Clear Zone .................................................. 3-253-23 C.7.f.1 Roadside Clear Zone Width ....... 3-263-243-243-23 C.7.f.2 Roadside Slopes ........................ 3-273-253-253-24 C.7.f.3 Criteria for Guardrail ................... 3-273-253-253-24 C.7.g Curbs ............................................................ 3-293-273-273-25 C.7.h Parking .......................................................... 3-293-273-273-25 C.7.i Right of Way ................................................. 3-293-273-273-25 C.7.j Changes in Typical Section ........................... 3-313-293-293-27 C.7.j.1 General Criteria .......................... 3-313-293-293-27 C.7.j.2 Lane Deletions and Additions ..... 3-313-293-293-27 C.7.j.3 Special Use Lanes ..................... 3-313-293-293-27 C.7.j.4 Structures ................................... 3-323-293-293-27 C.7.j.4.(a) Horizontal Clearance3-333-303-303-28 C.7.j.4.(b) Vertical Clearance3-333-303-303-28 C.7.j.4.(c) End Treatment ... 3-333-303-303-28 C.8 Access Control .............................................................. 3-343-313-313-29 C.8.a Justification ................................................... 3-343-313-313-29 C.8.b General Criteria ............................................. 3-343-313-313-29 C.8.b.1 Location of Access Points .......... 3-343-313-313-29 C.8.b.2 Spacing of Access Points ........... 3-353-313-313-29 C.8.b.3 Restrictions of Maneuvers .......... 3-353-323-323-30 C.8.b.4 Turn Lanes ................................. 3-353-323-323-30 C.8.b.5 Grade Separation ....................... 3-363-333-333-31 C.8.b.6 Roundabouts .............................. 3-363-333-333-31 C.8.c Control for All Limited Access Highways ....... 3-373-333-333-31 C.8.d Control of Urban Streets ............................... 3-373-343-343-32 Geometric Design 3-ii Topic # 625-000-015 DRAFT May - 2012007 Manual of Uniform Minimum Standards Printed 2/73/4/20110 for Design, Construction and Maintenance for Streets and Highways C.8.e Control for Rural Highways ........................... 3-383-353-353-33 C.8.f Land Development ........................................ 3-383-353-353-33 C.9 Intersection Design ....................................................... 3-393-363-363-34 C.9.a General Criteria ............................................. 3-393-363-363-34 C.9.b Sight Distance ............................................... 3-403-373-373-35 C.9.b.1 General Criteria .......................... 3-413-383-383-36 C.9.b.2 Obstructions to Sight Distance ... 3-423-393-393-37 C.9.b.3 Stopping Sight Distance ............. 3-433-403-403-38 C.9.b.3.(a) Approach to Stops3-433-403-403-38 C.9.b.3.(b) On Turning Roads3-433-403-403-38 C.9.b.4 Sight Distance for Intersection Maneuvers3-433-403-403-38 C.9.b.4.(a) Driver’s Eye Position and Vehicle Stopping Position3-453-423-423-40 C.9.b.4.(b) Design Vehicle ... 3-463-433-433-41 C.9.b.4.(c) Case B1 - Left Turns From the Minor Road ... 3-463-433-433-41 C.9.b.4.(d) Case B2 - Right Turns From the Minor Road and Case B3 – Crossing Maneuver From the Minor Road ........ 3-473-443-443-42 C.9.b.4.(e) Intersections with Traffic Signal Control (AASHTO Case D)3-473-443-443-42 C.9.b.4.(f) Intersections with All-Way Stop Control (AASHTO Case E)3-483-453-453-43 C.9.b.4.(g) Left Turns from the Major Road (AASHTO Case F)3-483-453-453-43 C.9.b.4.(h) Intersection Sight Distance References ......... 3-483-453-453-43 C.9.c Auxiliary Lanes .............................................. 3-493-463-463-44 C.9.c.1 Merging Maneuvers .................... 3-493-463-463-44 C.9.c.2 Acceleration Lanes ..................... 3-493-463-463-44 C.9.c.3 Exit Lanes................................... 3-503-473-473-45 C.9.d Turning Roadways at Intersections ............... 3-513-483-483-46 C.9.d.1 Design Speed ............................. 3-523-483-483-46 C.9.d.2 Horizontal Alignment .................. 3-523-493-493-47 C.9.d.3 Vertical Alignment ...................... 3-523-493-493-47 Geometric Design 3-iii Topic # 625-000-015 DRAFT May - 2012007 Manual of Uniform Minimum Standards Printed 2/73/4/20110 for Design, Construction and Maintenance for Streets and Highways C.9.d.4 Cross Section Elements ............. 3-533-493-493-47 C.9.e At Grade Intersections .................................. 3-533-503-503-48 C.9.e.1 Turning Radii .............................. 3-533-503-503-48 C.9.e.2 Cross Section Correlation .......... 3-543-513-513-49 C.9.e.3 Median Openings ....................... 3-543-513-513-49 C.9.e.4 Channelization ............................ 3-553-523-523-50 C.9.f Driveways ..................................................... 3-553-523-523-50 C.9.g Interchanges ................................................. 3-563-523-523-50 C.9.h Clear Zone .................................................... 3-573-543-543-52 C.10 Other Design Factors .................................................... 3-573-543-543-52 C.10.a Pedestrian Facilities ...................................... 3-573-543-543-52 C.10.a.1 Policy and Objectives - New Facilities3-583-553-553-53 C.10.a.2 Accessibility Requirements ......... 3-583-553-553-53 C.10.a.3 Sidewalks ................................... 3-583-553-553-53 C.10.a.4 Curb Ramps ............................... 3-593-563-563-54 C.10.a.5 Additional Considerations ........... 3-603-573-573-55 C.10.b Bicycle Facilities ............................................ 3-603-573-573-55 C.10.c Bridge Design Loadings ................................ 3-603-573-573-55 C.10.d Dead End Streets and Cul-de-sacs ............... 3-613-573-573-55 C.10.e Bus Benches and Transit Shelters ................ 3-613-583-583-56 C.10.f Traffic Calming .............................................. 3-613-583-583-56 C.11 Reconstruction .............................................................. 3-613-583-583-56 C.11.a Introduction ..................................................