A. 
General.
(1) 
This chapter presents criteria and guidelines for the design of roads, streets, driveways, and off-street parking lots. The criteria and guidelines have been developed considering the intended role of the street in relation to service function, land use, traffic demand, quality of service, vehicular and pedestrian safety, economy, and the environment.
(2) 
Tables 2.01.01 and 2.01.02 (Appendix A) give a summary of the basic design criteria which are developed in this chapter.[1]
[1]
Editor's Note: These tables are included as an attachment to this chapter.
B. 
Continuity of typical section. When a road is constructed in segments at various times or traverses varying zoning districts, the County may require certain design features (e.g., curb type, paving width, etc.) not otherwise required by this manual or may waive these design features in order to provide continuity of the typical section.
The three principal values controlling design of roads and streets are average daily traffic volume (ADT), design speed, and design vehicle. These values form the basis for the selection of the geometric elements that are required to accommodate the anticipated traffic at a desired quality of service.
A. 
Average daily traffic volume (ADT).
(1) 
Average daily traffic volume will be the design control as shown in Article VII, § 278-72, Functional classification of roads, of the Charles County Subdivision Regulations. In cases of lower classification of streets, trip generation rates may be used in lieu of average daily traffic.
B. 
Design speed.
(1) 
Design speed is the maximum safe speed that can be maintained over a given section of road when the traffic volume is so low that the geometrics of the roadway control speed. All elements should be in balance consistent with a specified design speed. Stopping sight distance, horizontal and vertical alignment, and superelevation are among the roadway elements which are controlled by design speed. The minimum design values for the various elements required for a given design speed should be used only where controls such as topography and property damages dictate their use. On local and minor collector residential streets it is desirable to keep speeds low, and care must be exercised that the design does not encourage high speeds without sacrificing any of the design standards included herein. Speed control measures shall be incorporated into the design of all residential local and minor collector roads longer than 1,500 feet which are located within the development district.
[Amended 5-12-2015 by Bill No. 2015-03]
(2) 
Unless otherwise approved by the County, the minimum design speeds listed in Tables 2.01.01 and 2.01.02 (Appendix A) shall be used for the design of roads.[1] For existing County roads whose classification is unknown the design speed shall be the posted speed plus 10 mph.
[1]
Editor's Note: These tables are included as an attachment to this chapter.
C. 
Design vehicle.
(1) 
The design vehicle is the motor vehicle whose characteristics determine such geometric elements as vertical clearance and turning radii. Vehicles have been divided into six classes and a typical design vehicle has been developed for each. The respective design vehicles have dimensions and a minimum turning radius larger than those of almost all vehicles in the respective classes.
(2) 
The six design vehicle designations are as follows:
(a) 
P (Passenger car).
(b) 
SU (Single-unit truck).
(c) 
BUS (Single-unit bus).
(d) 
WB-40 (Semitrailer combination, intermediate).
(e) 
WB-50 (Semitrailer combination, large).
(f) 
WB-60 (Semitrailer - full trailer combination).
(3) 
Dimensions and turning characteristics of each design vehicle are contained in Reference 1.[2]
(4) 
Though a road must be designed to accommodate the largest vehicle likely to use it, the selection of too large a design vehicle can have an adverse effect, such as longer crosswalks at the intersections. The design vehicle must be selected considering the street classification and adjacent land uses. Its selection is subject to review and approval by the County.
(5) 
In no case shall a public road, private road or commercial/industrial entrance be so designed that it cannot accommodate a WB-40 vehicle and a fire truck with an inside turning radius of 35.5 feet and an outside turning radius of 46 feet and an overhang of 2.5 feet.
A. 
Introduction.
(1) 
General.
(a) 
All roads should be designed to take full advantage of the existing topography and offer scenic views wherever possible.
(b) 
The horizontal and vertical alignment should be designed together to assure a smooth continuous route. Design procedures which include the careful coordination of the vertical and horizontal alignment will result in a safer, more aesthetic and more economical design. The horizontal curve should be longer than the vertical curve at a given location so that the driver can easily perceive changes in horizontal alignment. Sharp horizontal curves should be avoided at the bottom of long steep grades because vehicular speeds may be high, making it difficult to travel on the curve, especially under slippery conditions.
(c) 
The design for both horizontal and vertical alignment should be such that no unexpected features are presented to the driver. A sharp horizontal curve should not be introduced after a long stretch of tangents and flat curves; rather, the curves should become progressively sharper to accustom the driver to the larger centrifugal forces.
(2) 
Sight distance.
(a) 
Sight distance is the length of visible roadway ahead of the driver. The two types of sight distance considered in design are stopping (or nonpassing) sight distance and passing sight distance. Sight distance shall be made as long as feasible, but never less than the stopping sight distance.
(b) 
The sight distance required at intersections is presented in § 276-7F.
(3) 
Stopping sight distance.
(a) 
Stopping sight distance (SSD) is the distance required for a vehicle to stop before reaching an object in its path. It is the sum of the distance traveled from the moment the object is first visible to the driver to the moment the brakes are applied, and the distance required to stop after the brakes are applied.
(b) 
The equation for stopping sight distance is:
where:
V
=
initial speed, mph
F
=
coefficient of friction between tires and roadways for wet pavement
G
=
percent of algebraic grade divided by 100
(c) 
Stopping sight distances on a level roadway for various design speeds are shown in Table 2.02 (Appendix A).[1]
[1]
Editor's Note: This table is included as an attachment to this chapter.
(d) 
Stopping sight distance is measured between an eye height of 3.5 feet and an object height of six inches.
(e) 
The relationships between horizontal curvature and sight distance, and vertical curvature and sight distance, are given in Subsections C and G, respectively.
(4) 
Passing sight distance.
(a) 
Passing sight distance (PSD) is the distance required for a vehicle to pass another before meeting an opposing vehicle which might appear after the pass began. It is applicable only to two-lane, two-way rural major collectors, and minor arterials.
(b) 
Passing sight distance is measured between an eye height of 3.5 feet and an object height of 4.25 feet.
(c) 
The minimum passing sight distance should be provided at least once per mile.
(d) 
Table 2.10 (Appendix A) contains minimum passing sight distances for various design speeds.[2]
[2]
Editor's Note: This table is included as an attachment to this chapter.
B. 
Horizontal alignment.
(1) 
Intersection location and spacing.
(a) 
Roads should be so located that sufficient length is provided between intersections for weaving, storage, and associated land uses. The minimum intersection spacing, measured along the through roadway between the centerline of intersecting roadways, shall be as indicated in Table 2.03 (Appendix A).[3]
[3]
Editor's Note: This table is included as an attachment to this chapter.
(2) 
Cul-de-sac streets and turnarounds.
(a) 
The design of single access streets such as cul-de-sacs shall be as specified in Tables 2.01.01 and 2.01.02 (Appendix A).[4] Streets which are permanently designed with only one end open to traffic shall be terminated in a cul-de-sac as shown in the Charles County Standard Detail Manual. In the event a street will be extended in the future under a planned project for which a preliminary plan has been approved, a temporary "T" turnaround shall be provided as shown in the Charles County Standard Detail Manual R/2.19.
[4]
Editor's Note: These tables are included as an attachment to this chapter.
C. 
Horizontal curves.
(1) 
General.
(a) 
Horizontal curves are used to change direction at a safe rate and shall be used wherever the roadway centerlines change direction.
(b) 
Reverse curves and compound curves are a combination of simple curves and criteria governing their use are included in Subsection D.
(2) 
Degree of curve, superelevation, and design speed.
(a) 
The relationship between design speed, curvature and superelevation is:
where:
E
=
rate of superelevation, feet/feet
F
=
side friction factor
V
=
design speed, mph
R
=
radius of curve, feet
D
=
degree of curve
(b) 
The design speed shall be as set forth in Tables 2.01.01 and 2.01.02 (Appendix A).[5]
[5]
Editor's Note: These tables are included as an attachment to this chapter.
(c) 
Maximum superelevation rates are dependent upon the type of roadway, the effect of the superelevation upon vehicles operating at less than the design speed and drainage considerations.
(d) 
Roads designed with a design speed of 50 mph and greater shall be superelevated. The maximum superelevation rate to be used is 6%. Two-thirds of the superelevation runoff shall be placed on the tangent and 1/3 on the curve. Roads shall be superelevated in accordance with AASHTO standards.
(3) 
Horizontal sight distance.
(a) 
Another control on horizontal alignment is the sight distance across the inside of curves. Where there are sight obstructions such as building, trees, hedges, walls, guardrail, or cut slopes, efforts shall be made to provide as long a sight distance as feasible, but never less than the stopping sight distance given in Table 2.02 (Appendix A).[6]
[6]
Editor's Note: This table is included as an attachment to this chapter.
(b) 
Where there are no sight obstruction within the right-of-way, the right-of-way line shall be used as the sight obstruction or alternately by the inclusion of an easement on a record plat to maintain a clear line of sight zone.
D. 
General controls for horizontal alignment. In addition to the specific criteria presented in previous sections, the following general controls shall be utilized:
(1) 
In selecting the alignment for a given design speed, use of the maximum curvature (i.e., minimum radius) for that speed should be avoided except where beneficial for traffic calming purposes.
[Amended 5-12-2015 by Bill No. 2015-03]
(2) 
Consideration shall be given to the alignment and its effect on running speed. The speed at the bottom of a long downgrade, for example, will be higher than on a level grade, and this shall be considered when introducing a horizontal curve.
(3) 
The minimum radius of horizontal curves shall be as shown in Tables 2.01.01 and 2.01.02 (Appendix A).[7]
[7]
Editor's Note: These tables are included as an attachment to this chapter.
(4) 
Sharp curvature shall be avoided on long high hills. The absence of such reference items as cut slopes, trees, and buildings makes it difficult for the driver to judge horizontal curvature.
(5) 
In compound circular curves, the radius of the flatter curve should not be more than 1.5 times greater than the radius of the sharper curve.
(6) 
Where reverse curves are used, a minimum of 100 feet tangent shall be provided between the curves.
(7) 
Broken back curves, that is, two curves in the same direction separated by a short tangent, should be avoided.
E. 
Vertical alignment.
(1) 
Vertical alignment shall be designed considering the design speed and road classification in order to provide a balance between all geometric elements of the road.
(2) 
The two components of vertical alignment are grades and vertical curves. Minimum grades are established to assure adequate drainage, and maximum grades are established considering the operational characteristics of the design vehicle. Vertical curves must be at least long enough to provide the required stopping sight distance.
(3) 
Vertical alignment is controlled by a profile grade line (PGL) shown on the standard details.
(4) 
Control for profiles at intersections are contained in § 276-7G.
F. 
Grades.
(1) 
The minimum grade for all roads and streets shall be 1.0% unless otherwise approved by the County. Where a curbed section is used, the spacing of inlets must be carefully studied when utilizing the minimum grade to avoid the spreading of stormwater across the pavement.
(2) 
The maximum grade in a cul-de-sac bulb shall not exceed 6%.
(3) 
The maximum grade varies with road classification and is shown in Tables 2.01.01 and 2.01.02 (Appendix A).[8]
[8]
Editor's Note: These tables are included as an attachment to this chapter.
G. 
Vertical curves. Minimum lengths of vertical curves are shown on Table 2.04 (Appendix A).[9]
(1) 
Crest vertical curves. Crest vertical curves must be sufficiently long to provide the required stopping sight distance as listed in Table 2.02 (Appendix A).[10]
[10]
Editor's Note: This table is included as an attachment to this chapter.
(2) 
Sag vertical curves. Sag vertical curves must be sufficiently long to assure that a driver has sufficient distance in which to stop after his headlights first reveal an object on the roadway. Minimum lengths of sag vertical curves shall therefore be based upon a headlight sight distance equal to the stopping sight distance.
[9]
Editor's Note: This table is included as an attachment to this chapter.
H. 
General controls for vertical alignment. In addition to the specific criteria presented in previous sections, there are a number of general controls applicable to vertical alignment.
(1) 
In selecting the vertical alignment base on a given design speed, use of the maximum gradient and minimum length of curve for that speed should be avoided.
(2) 
The length of vertical curve shall not be less than three times the design speed in mph.
(3) 
The length of vertical curve shown in the linear profile around the cul-de-sac bulb at the curb line for closed section roadways shall not exceed 25 feet.
(4) 
A smooth profile grade, consistent with the topography, shall be strived for in preference to a grade with numerous breaks and short lengths of tangent.
(5) 
The profile shall be such that hidden dips hazardous to passing maneuvers are avoided.
(6) 
Short tangents of less than 50 feet between vertical curves shall be avoided.
(7) 
Where there is an at-grade intersection on a highway with a steep grade, the gradient should be reduced through the intersection to aid turning vehicles and reduce hazards. Specific criteria are contained in § 276-7G.
A. 
Typical sections.
(1) 
Unless otherwise approved by the County, typical paving sections for the various functional classifications are shown in Tables 2.01.01 and 2.01.02 (Appendix A).[1]
[1]
Editor's Note: These tables are included as an attachment to this chapter.
(2) 
Private drives. When provided for by the Zoning Ordinance and/or Subdivision Regulations,[2] for single-family detached residential lots, the following conditions apply:
[Amended 1-31-2017 by Bill No. 2016-10]
(a) 
Where two or more lots are proposed to be served by the same common access easement or private right-of-way, such common access easement or private right-of-way, shall have a minimum width of 30 feet.
(b) 
Parking spaces shall not be provided within that portion of private drives which serve two or more lots.
(c) 
The responsibilities for private drive maintenance shall be clearly stated in covenants, in a form acceptable to the Planning Commission, which shall be filed in the land records at the time of filing of the final plat, and a certification shall be included on the final plat to the effect that the subdivision is subject to covenants.
(d) 
For lots less than one acre in size, the drive shall be a minimum of two inches of asphalt pavement on six inches bank run gravel base. Curbing is not required. For lots one acre or more in size, the drive shall be a minimum of six inches bank run gravel. Where any drive connects with a county road, an entrance apron within the county right-of-way shall be constructed of two inches of pavement on six inches bank run gravel base.
(e) 
The minimum width of a private drive shall be as specified in Appendix Tables 2.01.01 and 2.01.02 (Appendix A).
(f) 
Private drives within a common access easement or private right-of-way shall be constructed at the time of construction of the subdivision and shall be constructed by the developer.
(g) 
A private drive shall end with a cul-de-sac or turnaround, as shown in the Charles County Standard Detail Manual R/2.57, for either of the following conditions:
[1] 
A common access easement or private right-of-way longer than 250 feet; or
[2] 
More than two lots are served by a private drive that has access from a public road classified as a minor collector, major collector or arterial.
[2]
Editor's Note: See Chs. 278, Subdivision Regulations, and 297, Zoning Regulations, respectively.
(3) 
Way. The maximum depth of a way shall be measured from the edge of the right-of-way line of the connecting road to the furthermost portion of the right-of-way. A way with curb and gutter may have a curbed or uncurbed island. A way with travel in two directions shall have a maximum depth of 300 feet. For ways with travel in one direction only, the maximum depth shall be 100 feet.
[Amended 1-31-2017 by Bill No. 2016-10]
(4) 
Court. A local road utilizing curb and gutter shall have a paved section of 24 feet in width.
[Amended 1-31-2017 by Bill No. 2016-10[3]]
[3]
Editor's Note: This bill also repealed former Subsection A(4), Place, and redesignated former Subsection A(5) and (6) as Subsection A(4) and (5), respectively.
(5) 
Alleys shall meet the following criteria:
(a) 
Layout. Alleys shall provide vehicular access to lots with frontage on a public road or frontage on a minimum twenty-four-foot-wide private road. Vehicular access shall be provided to both ends of an alley. No alley shall be more than 450 feet long between intersecting alleys or roads.
(b) 
Parking. Where parking on an alley is allowed, parking spaces shall be marked with paint striping outside the minimum travel lane width. Where additional parking width is not provided, "No Parking" signs shall be installed.
(c) 
Sight distance. Alleys shall provide minimum stopping sight distance in accordance with Table 2.02 (Appendix A).[4]
[4]
Editor's Note: This table is included as an attachment to this chapter.
(d) 
Vertical clearance. Unobstructed vertical clearance of 14 feet shall be provided overhead of the travel lane width.
B. 
Pavement widths and cross-slope. Roadway pavement widths and pavement cross-slopes shall be as shown on the typical sections. The minimum cross slope of cul-de-sacs from the center point to any radial portion of the cul-de-sac bulb must be 1%.
C. 
Pavement thickness. Specific criteria are contained in § 276-10.
D. 
Curb and gutter.
(1) 
Concrete curb and gutter shall be provided in residential subdivisions where the average lot frontage is less than 100 feet, and in front of all commercial and industrial lots or parcels, or where required by the State Highway Administration for properties fronting on state roads.
(2) 
Curb and gutter shall meet the requirements of the standard details.
(3) 
The following are the permitted uses of the various types of curb:
(a) 
Eight-inch standard combination curb and gutter: Any street.
(b) 
Modified combination curb and gutter or six-inch standard combination curb and gutter: Local roads, and minor collector roads in residential subdivisions.
(c) 
Bituminous curb: Provide in parking lots, private drives, in areas where curbing is not specifically required under Subsection D(3)(a) above and as temporary construction, transitions for roads not built to ultimate section or to provide continuity of road section.
(d) 
Standard barrier (header) concrete curb: Traffic islands, private parking lots, and private roads.
(e) 
Special designs: Granite blocks, precast curb (wheel stops), steel curb, pressure-treated wood, monolithic curb/sidewalk, or other alternate curbing design may be used on private parking lots and private drives or with prior approval of the County.
E. 
Shoulders. Shoulders shall be as shown on the typical sections. Paved shoulders are required for public streets in the Development District Residential Zones (RL, RM, RH, and RO), and in planned development zones, including PUD and WPC zones.
F. 
Medians. Medians shall be as shown on the standard details. Raised medians six feet or less in width should have a paved surface.
G. 
Pedestrian travel ways: Refer to the Charles County Standard Detail Manual. For the design of biker paths inside the right-of-way or outside the right-of-way, refer to the most recent AASHTO "Guide for the Development of Bicycle Facilities." (Reference 5[5].)
(1) 
Sidewalks/hiker-biker paths.
(a) 
Areas normally requiring sidewalks are so indicated on the typical sections contained in the Standard Detail Manual R/2.10 through R/2.16.1. The minimum pedestrian walk width shall be four feet outside the urban road standards district. Where there will be a large number of pedestrians, such as near schools and in some commercial areas, the pedestrian paths shall be made sufficiently wide to accommodate the anticipated pedestrian demand. The selection of a pedestrian walk width in such areas is subject to review and approval by the County.
(b) 
Typically, a hiker-biker path will be part of a continuous, comprehensive link, as opposed to the conventional concrete sidewalk. Residential areas, school and open space areas, and short routes connecting residential and employment centers typically warrant provisions for pedestrians/bicyclists.
(c) 
Hiker-biker paths shall be (a) separated from the roadway but within the street right-of-way, or (b) within open space. The County shall be consulted when planning a hiker-biker path within or adjacent to a street right-of-way. When planning pedestrian travel ways, the County shall be consulted to provide coordination between the planned pedestrian travel ways and those in surrounding areas.
(d) 
Construction of a community comprehensive pedestrian travel way network may result in a waiver of conventional sidewalk requirements as per the approval of the Planning Commission.
(e) 
Where hiker-biker paths intersect with vehicular roadways, a visible indicator such as road striping and/or signage should be provided as per the most recent MUTCD standards. Access to hiker-biker paths by motor vehicles shall be discouraged by use of physical barriers, signage, or grade separations where practical.
(2) 
Maintenance of pedestrian travel way.
(a) 
Within the designated Urban Road Standards District (Appendix G),[6] if any portion of the pedestrian travel way is outside of the right-of-way and associated easement or contains any amenities such as street furniture, dining tables, benches, etc., then the abutting property owner, homeowners' association (HOA) or other association as approved by the County is responsible for maintenance of the entire pedestrian travel way, including all amenities within. An easement document will be executed between the adjoining property owner or respective HOA and the County to define maintenance requirements, installation of utilities, and public access rights.
[6]
Editor's Note: Said appendix is included as an attachment to this chapter.
(b) 
Maintenance for hiker-biker paths and all sidewalks within subdivisions which are located within the County right-of-way, both of which were designed and constructed in accordance with the 1995 Road Ordinance or more recent revision, shall be the responsibility of Charles County.
(c) 
It is the responsibility of the abutting property owners, the respective homeowners' association or other association as approved by the County to remove snow and ice from the hiker-biker paths and sidewalks.
H. 
Side slopes.
(1) 
Side slopes for excavations and embankments should be as flat as feasible considering earthwork and right-of-way requirements. The normal maximum slope shall be 2:1. Where poor soil conditions exist, soil tests and a slope stability analysis shall be conducted to determine an acceptable slope.
(2) 
All slopes shall be covered with topsoil and seeded and mulched.
I. 
Guardrail.
(1) 
Guardrail shall be required when combinations of embankment slope and height warrant guardrail for open sections as shown in Appendix B.[7] Wherever feasible, the embankment should be adjusted to eliminate the need for guardrail. Where guardrail is warranted, it shall be placed as shown on the typical sections and shall conform to the Maryland State Highway Administration Standard Details.
[7]
Editor's Note: Said appendix is included as an attachment to this chapter.
(2) 
Factors to be considered when determining the need for guardrail at fixed roadside objects include design speed, roadway functional classification, type of obstacle, and distance from pavement edge to the obstacle. The determination of need for guardrail is subject to review and approval by the County.
J. 
Utility location. The locations for the placement of utilities within the road right-of-way are shown in the Standard Details Manual R/2.20. Where conditions are such that the use of the normal location arrangements would be infeasible, an alternate arrangement shall be developed and submitted to the County for review and approval. All utility owners shall have their utility installation plans approved by the County before any construction work is commenced.
A. 
Introduction. To assure that an intersection is designed to safely and efficiently accommodate the traffic desiring to use it, certain procedures and analyses must be performed. This section contains the geometric design elements applicable to intersections, the procedures to be followed in developing the best possible design layout and the information required on the construction drawings.
B. 
Geometric design.
(1) 
Skew angle and horizontal curvature.
(a) 
Roadway centerlines shall intersect as closely as possible to right angles with a maximum skew of 70° and continue through the intersection without offset or break, unless otherwise approved by the County.
(b) 
Where the radius of the horizontal curve of a street approaching an intersection is less than or equal to 300 feet, a tangent at least 50 feet long shall be placed between the flowline of the intersecting street and the P.C. of the curve.
(2) 
Design vehicles and turning paths. Many intersection design details, such as curb radii and island locations, depend upon the choice of the design vehicle. The larger design vehicles require larger curb radii and wider lane widths between islands than do the smaller vehicles. Selection of the design vehicle depends upon the functional classifications of the intersecting streets, adjacent land use, and volume and type of vehicles that will use the intersection. Turning paths for the various design vehicles are shown in A Policy on Geometric Design of Highways and Streets (Reference #1 of Appendix H).[1]
[1]
Editor's Note: The Annotated Code of Maryland, Article 56, was repealed by Acts 1996, c. 10, § 15, effective April 9, 1996.
(3) 
Minimum curvature for turning movements. Table 2.05 (Appendix A) shows the minimum fillet radius (either curb or edge of roadway) which will permit a design vehicle to make a ninety-degree turn both with and without encroachment upon adjacent lanes.[2]
[2]
Editor's Note: This table is included as an attachment to this chapter.
C. 
Auxiliary lanes/turning lanes.
(1) 
General. The provision of auxiliary lanes shall be required under any of the following conditions for either public or private access points onto a public road:
(a) 
The level of service analysis indicates a need for auxiliary lanes.
(b) 
The difference between the design speeds of the through roadway and turning roadway exceeds 20 mph and signalization is not provided.
(c) 
The design speed of the roadway is 40 mph or greater and vehicles waiting to turn left or right would pose a hazard to through traffic.
(2) 
Exceptions. If the project is exempt from providing a traffic study in accordance with the Adequate Public Facilities section of the Zoning Ordinance,[3] auxiliary lanes will not be required.
[3]
Editor's Note: See Ch. 297, Zoning Regulations.
(3) 
Width and length.
(a) 
Auxiliary lanes shall be 12 feet wide. In closed sections, this width shall be measured to face of curb.
(b) 
On closed sections, the taper of an auxiliary lane shall consist of reverse symmetrical curves. On open sections, the taper may consist of either full width or a straight line.
(c) 
The minimum lengths required for auxiliary lanes and taper are shown in Table 2.11 (Appendix A).[4] If storage length, based on traffic volume, exceeds the required length of deceleration lane (excluding taper), greater deceleration lane length shall be provided.
[4]
Editor's Note: This table is included as an attachment to this chapter.
D. 
Median lanes and openings.
(1) 
A median lane is a left-turning auxiliary lane located within the median, and the determination of its need, as well as its geometries, such as length and width, shall be as for any auxiliary lane.
(2) 
The design of the median opening shall normally be based upon a fifty-foot radius tangent to the median edge and crossroad centerline. Where an opening will be used by a large number of turning trucks, such as in commercial or industrial areas, a radius of 75 feet shall be used. (Refer to Standard Detail R/2.2.1.)
(3) 
The median opening design should be checked to assure that opposing left turns can be made without conflict.
(4) 
A semicircular end shall be used on all median islands six feet or less in width. For widths greater than six feet, a bullet nose shape shall be used.
E. 
Traffic islands.
(1) 
Traffic islands are areas between traffic lanes used for controlling vehicle movements or for pedestrian refuge. All islands with an area of at least 75 square feet shall be raised and bounded by a standard curb or combination curb and gutter. Islands with areas less than 75 square feet shall have a normal pavement section and be marked by paint.
(2) 
Divisional islands, which are islands separating opposing traffic flows within the intersection area, shall be a minimum of four feet wide. The offset from the edge of travel lane to the approach nose shall be least three feet.
(3) 
The approach noses of traffic islands may be depressed to two inches above the pavement if approved by the County.
(4) 
On islands adjacent to turning roadways, the approach nose shall be offset at least four feet from the edge of the adjacent through lane and a minimum of two feet from the edge of the turning roadway.
(5) 
The nose radii of triangular islands shall be two feet, except the right angle corner, which shall have a five-foot radius. The approach nose of divisional islands shall have a one-foot radius, offset as discussed above. The end of a divisional island shall be in accordance with median openings.
(6) 
All divisional islands six feet or less in width, as well as triangular islands of less than approximately 150 square feet, shall be paved. Divisional islands wider than six feet, and triangular islands greater than 150 square feet in area, shall be seeded and mulched. Sidewalks shall be included where directed by the Office of Planning.
F. 
Intersection sight distance.
(1) 
At signalized intersections, the movements are controlled and provision of the stopping sight distance as given in Table 2.02 (Appendix A) is sufficient.[5]
[5]
Editor's Note: This table is included as an attachment to this chapter.
(2) 
The following criteria have been established for the determination of unsignalized intersection sight distance:
(a) 
Crossing movement. Sufficient distance, both left and right, to enable a stopped vehicle to cross the intersection before a vehicle on the major highway reaches the intersection, even though this vehicle appears just as the crossing maneuver begins, and without the through vehicle have to decelerate.
(b) 
Left turn. Sufficient distance on the left to enable a stopped vehicle to turn left onto the major road before a vehicle approaching from the left reaches the intersection, even though this vehicle appears just as the left turn begins, and without the through vehicle having to decelerate. Also, sufficient distance on the right to enable a stopped vehicle to turn left onto the major road without a vehicle on the major road, approaching from the right, having to decelerate more than 10 mph, even though the approaching vehicle appears just as the turn begins.
(c) 
Right turn movement. Sufficient distance on the left to enable a stopped vehicle to turn right onto the major road without a vehicle on the major road, approaching from the left, having to decelerate more than 10 mph, even though the approaching vehicle appears just as the turn begins.
(3) 
The minimum sight distance for each of these criteria are given in Table 2.06 (Appendix A).[6]
[6]
Editor's Note: This table is included as an attachment to this chapter.
(4) 
The possible movements at each intersection shall be determined and appropriate sight distance selected from Table 2.06 (Appendix A).[7]
[7]
Editor's Note: This table is included as an attachment to this chapter.
G. 
Intersection vertical alignment.
(1) 
General. Typical section pavement slopes of the street with the higher functional classification shall be carried through the intersection without deviation. The pavement slopes of the street with the lower classification shall be warped to meet the pavement edge of the through street. Where two roads of the same classification intersect, they shall be connected by considering one the more important and transitioning the other as stated above, or by transitioning both roadways.
(2) 
Intersection grades. As discussed above, one of the intersecting roads shall be determined to be the more important and its grade carried through the intersection without interruption. The grade of the other road as it approaches the through road shall have a landing grade meeting the following criteria:
Functional Classification
Maximum Grade Through Intersection
Distance From Intersection(1)
(feet)
Arterial
3.0%
200
Collector
3.0%
175
Local streets
4.0%
40
(1)Distance measured from pavement edge of intersecting road to the PVC of the vertical curve.
H. 
Pedestrian facilities. Ramps for pedestrians shall be provided at all intersections and other major points of pedestrian flow having sidewalks. Typical ramps are contained in the Standard Details Manual. Ramps shall meet federal, state, or local requirements as applicable. (Reference Detail R/2.29.)
I. 
Right-of-way at intersection. The right-of-way lines at intersections shall be adequate to accommodate all the required design features but shall not be less than that required by the latest Subdivision Regulations.[8]
[8]
Editor's Note: See Ch. 278, Subdivision Regulations.
J. 
Intersections with state highways. Criteria and permits related to intersections with state highways are contained in the Maryland State Highway Access Manual.
A. 
To obtain uniformity and maximum safety, the design and location of commercial and industrial entrances shall be in accordance to the standards set forth in the Maryland State Highway Access Manual of the Maryland State Highway Administration. Entrances shall be as shown in the Standard Details Manual.
B. 
Permit procedures for entrances or any work performed within County right-of-way are outlined in § 276-18.
A. 
Off-street parking lots must be designed to accommodate the anticipated demand, provide parking stalls of sufficient size to accommodate the vehicles, and provide safe and convenient traffic flows.
B. 
The width and number of stalls shall be as required by the Charles County Zoning Regulations.[1]
[1]
Editor's Note: See Ch. 297, Zoning Regulations.
C. 
The parking lot design shall discourage random movements and, through the use of traffic engineering aids such as signs and islands, provide positive guidance to the motorists. Efforts shall be made to minimize vehicular and pedestrian conflicts. All parking lot designs shall be considered at the time of site plan review by the County.
D. 
Parking for the handicapped shall be provided in all off-street parking lots in accordance with the Charles County Zoning Ordinance[2] and in accordance with federal or state requirements.
[2]
Editor's Note: See Ch. 297, Zoning Regulations.
E. 
Pedestrian ramps should be located so as to provide easy and direct access between the handicapped parking spaces and the building entrance.
F. 
The paving section of parking lots shall be in accordance with Table 2.07 (Appendix A) and the Standard Details.[3]
[3]
Editor's Note: This table is included as an attachment to this chapter.
G. 
Private roads, private drives, alleys, parking aisles and commercial/industrial driveways shall be designed to provide an unobstructed route for fire truck access to buildings and fire hydrants. Refer to § 276-4C for fire truck design vehicle characteristics.
A. 
At-grade golf cart crossings shall only be permitted on local residential public streets. The local residential public street shall not carry through traffic and shall be an internal subdivision road. Stop signs shall be placed on the golf cart path at their intersection with the local road. The at-grade crossing shall be treated as a pedestrian crossing and advanced crossing signs (with golf cart logo) and other appropriate signage and pavement markings shall be installed as per MUTCD.
B. 
The roadway and golf cart path centerline shall intersect as closely as possible at right angles to the public road with a maximum skew of 70° and continue through the intersection without offset or break. The golf cart path shall be tangent inside the public right-of-way. The maximum grade of the golf cart path in the public right-of-way shall not exceed 3%. The sight distance at the intersection shall meet the requirements of this chapter.
C. 
Golf cart paths shall be constructed with asphalt or concrete surface within the public right-of-way. The minimum paved width of the path shall be 12 feet. The minimum cross slope for paved surface shall be 1%. The pavement material shall be placed upon 95% compacted subgrade. The pavement material detail shall be as follows:
(1) 
Asphalt path: six inches CR6 with three-inch surface asphalt SF.
(2) 
Concrete path: six inches concrete (mix #2) with six-by-six #10 wire mesh.
Roundabouts shall be designed in accordance with the most recent Maryland State Highway Administration Roundabout Design Guidelines.
A. 
School bus turnarounds shall be provided for residential subdivisions in accordance with the latest Policy # 3700 (Transportation) of Series 3000 of Policies Regulations By-laws of Board of Education of Charles County. The location of school bus turnarounds shall be shown on the approved Preliminary Plan of Subdivision.
B. 
A cul-de-sac of a minimum sixty-foot paved radius is required for school bus turnarounds.
A. 
Policy in general. The access management policy defines locations for future median openings and access points for certain roads within the County. As residential, business, industrial, and commercial establishments develop or redevelop land adjacent to the access managed roads, there is an interest in how these properties gain access to the road. Where applicable, properties that develop or redevelop along an access managed roadway will be required to consolidate access points to both the property itself and the adjacent properties. Minimizing access points will increase safety and level of service of the roadway.
B. 
Locating median openings and access points. Median openings, intersections, and property access points will be determined by the Board of County Commissioners for designated County roadways. The tables in Appendix F designate median openings and access points for select roadways by location or distance from a known point.[1]
(1) 
Access points. Access points will be one of two types: an intersection (median break) or right-in/right-out (no median break).
(a) 
Intersection (median break). The intersection shall consist of a median break to allow traffic to enter and exit a roadway from an adjoining or adjacent roadway. Access points which line up with the median openings may be either public roads or private driveways.
(b) 
Right-in/right-out (no median break). Right-in/right-out access points will be assigned to areas that are less than 1,320 feet from the nearest intersection or to an adjoining roadway of a low traffic volume. A minimum separation of 750 feet from adjacent access points is used wherever possible.
(2) 
Standards.
(a) 
Median openings on the four-lane road are predetermined at locations that are approximately 1,320 feet to 1,500 feet apart. Right-in/right-out access points are approximately 750 feet apart from adjacent access points.
(b) 
All median openings, intersections, and access points to access managed roadways will be at predetermined locations as shown in the table for the corresponding roadway in Appendix F.[2]
[2]
Editor's Note: Said appendix is included as an attachment to this chapter.
(c) 
The access points for developing and redeveloping properties will be consolidated within the property and any adjacent properties, wherever possible.
(d) 
All station numbers in the tables of Appendix F correspond to those on approved plan sheets.[3] If station numbers are not used, distances from known intersections will be given.
[3]
Editor's Note: Said appendix is included as an attachment to this chapter.
(e) 
For each access point listed in the tables of Appendix F, the determination of a median opening is indicated with a "yes" or "no" in the column titled "Median Opening." "Yes" indicates that a median opening exists or has been predetermined for the subject location. "No" indicates that the subject location is determined to have right-in/right-out access only.
(3) 
Inter-parcel connections. Developers shall provide inter-parcel connections to adjacent properties where they would provide alternative access to the properties and serve to minimize direct access to the access managed roadway.
(4) 
Access point adjustments. All locations are approximate and may be subject to adjustment based on engineering. The adjustment of an access point location up to 25 linear feet may be approved by the County Engineer. An access point adjustment greater than 25 linear feet will require a modification pursuant to Subsection C of this section.
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
C. 
Addition to or modification of Access Management Tables. The County Commissioners, in their capacity as the chief executive body of the Charles County Government, are hereby authorized to add to or modify Appendix F of the Charles County Road Ordinance, "Access Management Tables," from time to time, as circumstances warrant, in accordance with procedures to be adopted by the County Commissioners.[4]
[4]
Editor's Note: Said appendix is included as an attachment to this chapter.