(1) Design Details

(a) The Department may authorize or require certain changes in the design limits herein when such changes are necessary to preserve the normal and safe movement of traffic or to permit reasonable access.  When physical factors make it impractical to obtain reasonable access within these requirements, appropriate variations may be authorized after review of the proposed approach design by the Chief, Preconstruction Bureau.  Sight distance, as controlled by the design speed of the highway, must be maintained in all cases.  The following diagram illustrates required sight distances along major highways:

 

SIGHT DISTANCE AT INTERSECTIONS

 

(b) Design details should conform to the "Standard" charts or be within the "Range" charts for public approaches, right turn lanes and tapers or private approaches.  These charts are available from the Department of Highways upon request.

(2) Location

(a) Location of approaches shall be selected to first provide maximum safety for highway traffic and secondly, to provide convenience for users of the highway.

(b) All parts of entrances and exits, including the radii but not including right-turn lanes and tapers on highway right-of-way, shall be confined entirely within the permittee's property frontage.

(3) Materials - The permittee shall furnish all materials necessary for the construction of the approaches and appurte­nances authorized by the permit. This shall include drainage pipe, curb and gutter, concrete sidewalks, topsoil or sod, etc., as required. All materials, including base and surfac­ing, shall be of satisfactory quality and shall be subject to inspection and approval by the Department.

(4) Base and Surfacing - It shall be the responsibility of the permittee to supply, place, and properly compact the approach fill and base material. All base material shall con­sist of sand, sand-gravel or sand and rock mixtures containing the sufficient granular fines to fill the voids between the larger gravel and stone, and to permit compaction. In areas without curb and gutter, the approach base and surfacing shall consist of an adequate depth of granular material. When deemed necessary by the Department for maintenance or operational pur­poses, the property owner shall furnish and place bituminous surfacing. This surfacing should normally extend a minimum distance of 12 feet from the outside shoulder line or to the right-of-way line, whichever is less. Any distance to the right-of-way line beyond 12 feet should be gravel surfaced. Infrequently used field approaches may extend a lesser dis­tance. A 5-foot minimum is recommended. Commercial approaches are normally required to be surfaced.

(5) Corner Clearance - Corner clearance at the inter­section of a state highway with another highway or street approach shall provide for a sufficient distance from the intersection to preserve the normal and safe movement of traf­fic through it. If. the driveway is to be located adjacent to a highway or street intersection, the following requirements shall apply:

(a) Curbed - If the intersecting highway is curbed, the end point of curvature of the driveway radius shall be a mini­mum distance of 20 feet from the end point of curvature of the intersecting highway radius, or a minimum distance of 10 feet inside the abutting property frontage, whichever will provide the greater distance.

(b) Uncurbed - If the intersecting highway is uncurbed, the end point of curvature of the driveway radius shall be a minimum distance of 50 feet from the edge of pavement of the intersecting highway, or a minimum distance of 10 feet inside the abutting property frontage, whichever will provide the greater distance.

(c) Signalized - At signalized intersections or those determined by the Department to have potential for signali­zation, the near side corner clearance shall be a minimum distance of 30 feet (curbed section) and 40 feet (uncurbed sec-tion) from the end point of the driveway radius or inside the abutting property frontage. Far side clearance should be a minimum of 20 feet.

(6) Drainage

(a) Drainage in highway ditches shall not be altered or impeded except as noted under subsection 7. When drainage structures are required, size of opening, length of pipe and other design features must be approved by the District Engineer.

(b) All approaches shall either drain away from the trav-eled way or have sufficient crown to cause all drainage to run to the sides of the approach rather than drain onto the high-way. Approaches shall also be constructed so as not to impair drainage within the highway right-of-way, to alter the stabil-ity of the roadway subgrade or materially to alter the drainage of the areas adjacent to the highway right-of-way. Culverts and drop inlets shall be installed where required and shall be the type and size specified by the Department. Where the border area is regraded and/or landscaped, it shall have sufficient slope, culverts and drop inlets for adequate drainage.

(7) Safety or Buffer Zone - The safety or buffer zone shall include all parts of the highway right-of-way between the curb or shoulder line and the right-of-way line along the permittee's property frontage except the areas contained in the approaches. The safety zones adjacent to an approach may be filled in provided the requirements for drainage and the fol­lowing requirements are fully complied with:

(a) The filled-in area shall be sufficiently delineated with curbs, guardrails or delineators to prevent use of the area for parking or travel. Reflectorized delineators in rural areas are desirable.

(b) The filled-in area should extend from behind the sidewalks, or where no sidewalk exists, as provided in the permit. Provisions will be made by the Department to provide conformance with proposed future improvements to the existing highway section.

(c) When physical barriers are installed within the safety zone, they shall be installed according to the appropri­ate Department Standard Drawing. The barrier line nearest the highway shall be on line with existing curbs, or established curb line, provided the District Engineer or his authorized representative does not require a greater distance when needed to preserve the safety and utility of the highway or provided conformance with proposed highway improvements.

(d) An attempt should be made to provide an aesthetically pleasing safety zone by grading and seeding where possible. The placing of ground cover and use of other beautification principles is desirable; however, planting trees and shrubs that may in the future restrict sight distance will not be allowed.

(8) Approach Grade

(a) The approach grade or slope of the approach shall be constructed to conform to the slope of the roadway shoulder from the edge of the traffic lane to the shoulder line and thence shall be sloped downward within the range of .02 ft./ft. to .08 ft./ft. for a distance necessary to place the low point of the driveway approximately 8 inches below the shoulder ele­vation.

(b) On curbed sections of the highway, if the maximum allowable slope shown is not great enough to bring the approach to the level of the sidewalk, a depressed sidewalk may be con­structed. The connection between the original sidewalk and the depressed sidewalk shall be made through a warped section, the slope of which shall not vary more than 6 percent from the longitudinal grade of the original sidewalk. All new curbs and sidewalks should be constructed to the line and grade of the existing curb or sidewalk with every effort to construct a sidewalk that is level and free of dips. The maximum gradient limits beyond the outer edge of the sidewalk shall be the same as for uncurbed approaches.

(c) Where approaches have side slopes, these slopes should be constructed at a 6:1 ratio or flatter.

(9) Setback Distance

(a) The setback distance from the right-of-way line to the nearest edge of gas pump islands, vendor stands, tanks, water hydrants and other improvements should be at least 15 feet. A greater distance is recommended in rural areas where free movement of large vehicles is anticipated.

(b) Sufficient storage area off the highway right-of-way shall be provided by the landowner to prevent the servicing, stopping and storing of vehicles on the approach and to prevent a vehicle from backing out of an approach onto the traveled way. This requirement is especially applicable to parking lots, gas stations, garages, drive-in cafes, drive-in theatres, truck terminals and other roadside businesses' where a large number of vehicles enter and leave the property in a short period of time. Where necessary to prevent vehicle encroach­ment on the highway right-of-way, physical barriers may be installed on the right-of-way line. Such barriers are to be installed so as not to constitute a hazard to pedestrian or vehicle traffic.

(c) Poles, signs, displays, etc., which may restrict the sight distance of a vehicle entering or leaving the establish­ment, may not be installed between the right-of-way line and the setback line.

(10) Dedicated Streets

(a) A dedicated street or roadway is considered to be a public approach and shall comply with all applicable regula­tions. The only exception is that the width of the approach can be widened to match the street; however, the width of the

street surface should be governed by the expected traffic vol-umes and not the street right-of-way width.

(b) Developers of subdivisions or housing tracts shall obtain approval from the local unit of government having jurisdiction over the dedicated street or road. The governmental unit shall then submit the approach application to the Department.

(11) High Volume Rural Access - Those access approaches which will generate 25 or more left turning vehicle movements per peak hour entering the facility, or have the obvious poten­tial for expansion to this level, should be designed to the shape and dimensions of Department standards for high volume approaches.

(12) Mail Box Locations - Mail boxes placed along non-controlled access highways are a potential hazard to out-of-control vehicles. This hazard should be minimized by utilizing the following guidelines:

(a) Mail boxes should be similar in size, weight, and material to boxes approved by the United States Postal Service.

(b) The supports should not be larger than 4" x 4" tim­ber, 2" pipe or equivalent strength material.

(c) Unusual post design is discouraged. The weight of any support should not exceed 30 pounds, including the portion in the ground.

(d) If a concrete foundation is used, the top of the foundation should not project more than 4 inches above ground.

(e) No more than 3 mail boxes may be mounted on one post.

(f) Mail boxes should be mounted 38 inches vertically from edge of shoulder to bottom of the box. The lateral clearance should be a minimum of 18 inches and a maximum of 24 inches.