HARFORD COUNTY DEPARTMENT OF PUBLIC WORKS ROADWAY & STORMDRAIN DESIGN STANDARDS DECEMBER 2, 2008 HARFORD COUNTY DEPARTMENT OF PUBLIC WORKS ROADWAY & STORMDRAIN DESIGN STANDARDS Section I Roadway Design Standards Section II Stormdrain Design Standards Appendix I Roadway Design Tables/Charts Appendix II Stormdrain Design Tables/Charts Appendix III Standard Abbreviations and Symbols Appendix IV Roads and Stormdrain Review Check List Appendix V Rules and Regulations for Road Access Permits Appendix VI Rules and Regulations for Utility Construction Permits Appendix VII Sight Distance Requirements REVISED-EFFECTIVE DECEMBER 2, 2008 SECTION I HARFORD COUNTY DEPARTMENT OF PUBLIC WORKS ROADWAY DESIGN STANDARDS REVISED-EFFECTIVE DECEMBER 2, 2008 SECTION I HARFORD COUNTY DEPARTMENT OF PUBLIC WORKS ROADWAY DESIGN STANDARDS I. DEFINITIONS ...............................................................................................................R-1 II. GENERAL......................................................................................................................R-7 A. Introduction..........................................................................................................R-7 B. Waivers ................................................................................................................R-7 C. Philosophy of the Design Manual - Professional Creativity................................R-7 1. Capital Projects........................................................................................R-7 2. Development Projects..............................................................................R-7 D. Roadway Classification.......................................................................................R-8 1. Interstate...................................................................................................R-8 2. Parkway....................................................................................................R-8 3. Arterial .....................................................................................................R-8 a. Urban Principal Arterial...............................................................R-8 1) Freeway and Expressway.................................................R-8 2) Other Urban Principal Arterial ........................................R-8 b. Urban Minor Arterial...................................................................R-8 c. Rural Principal Arterial................................................................R-8 d. Rural Minor Arterial ....................................................................R-8 4. Collector...................................................................................................R-8 a. Urban Collector............................................................................R-8 b. Rural Major Collector..................................................................R-8 c. Rural Minor Collector..................................................................R-8 5. Local ........................................................................................................R-8 a. Business District Roads ...............................................................R-8 b. Residential Road Classifications .................................................R-9 1) Residential Collectors......................................................R-9 2) Residential Sub-collectors.............................................R-10 3) Residential Access Streets .............................................R-11 4) Town House Access.......................................................R-12 III. ROADWAY/TRAFFICWAY DESIGN .....................................................................R-13 A. Preliminary Considerations................................................................................R-13 B. Determination of the Typical Section................................................................R-13 C. Modification of Typical Section or Design Criteria ..........................................R-13 D. Intersection Criteria ..........................................................................................R-14 1. Intersection of County Roads ................................................................R-14 2. Intersection with State Roads ................................................................R-15 3. Residential/Commercial/Industrial Entrances.......................................R-15 REVISED – EFFECTIVE DECEMBER 2, 2008 4. Auxiliary Lanes......................................................................................R-16 a. Deceleration Lanes………….……………………………………R-16 b. Left Turn Lanes…………………………………………………..R-17 c. Acceleration Lanes……………………………………………….R-17 E. Sight Distance....................................................................................................R-17 1. Stopping Sight Distance.........................................................................R-17 2. Intersection Sight Distance ....................................................................R-17 a. New Intersections within a Subdivision……………………………R-18 b. New Intersections with Existing County Roads……………………R-18 F. Cul-de-sacs/Temporary Tee Turn-Arounds.......................................................R-18 1. Cul-de-sacs.............................................................................................R-18 2. Temporary Tee Turn-Arounds...............................................................R-19 G. Road End Signing ..............................................................................................R-19 H. Maintenance of Traffic Plan ..............................................................................R-19 I. Alleys ………………………............................................................................R-20 J. Bus Stops...........................................................................................................R-20 IV. GEOMETRICAL DESIGN ........................................................................................R-21 A. County Roads Excluding Town House Roads..........................................................R-21 1. Horizontal Alignment ............................................................................R-21 a. Horizontal Curves......................................................................R-21 1) Design Speed Minimum Radii .............................................R-21 2) Curve Data............................................................................R-21 3) Minimum Curve Length .......................................................R-21 4) Reverse Curves.....................................................................R-21 5) Compound Curves ................................................................R-21 6) Curve Widening....................................................................R-21 b. Driveways/Panhandles...............................................................R-21 c. Commercial and Industrial Entrances........................................R-22 d. Intersection Geometry................................................................R-23 e. Special Design Elements ...........................................................R-23 1) Roundabouts ..................................................................R-23 2) Monumental Entrances..................................................R-24 3) Divided Roadways.........................................................R-24 a) Residential Divided Roadways..................................R-24 b) Commercial Divided Roadways................................R-25 2. Vertical Alignment ................................................................................R-25 a. Grades ........................................................................................R-25 1) Minimum........................................................................R-25 2) Maximum.......................................................................R-25 3) Profile Grade Line .........................................................R-25 b. Intersection Criteria ...................................................................R-26 1) Intersection with County Roads.....................................R-26 2) Intersections with State Roads.......................................R-26 c. Vertical Curves..........................................................................R-26 REVISED – EFFECTIVE DECEMBER 2, 2008 1) Use of Vertical Curve ....................................................R-26 2) Design ............................................................................R-26 3) General Controls............................................................R-27 d. Linear Profiles............................................................................R-27 1) Minimum Grade.............................................................R-27 2) Minimum Curve Length ................................................R-27 e. Super-Elevation and Transitioning ............................................R-27 B. Town House Roads............................................................................................R-28 1. Horizontal Alignment ............................................................................R-28 2. Vertical Alignment ................................................................................R-28 3. Cross Slope............................................................................................R-28 4. Perpendicular