A driveway shall be so located that it will cause no undue interference with the free movement of the traveling public and provide the most favorable vision and grade conditions possible for motorists using the roadway. The driveway shall be consistent with the development of the site considering proper traffic operations and safety. MAKE SURE THE LOCATION SELECTED WILL PROVIDE THE BEST AVAILABLE SIGHT DISTANCE.
A driveway, including the radii but not including the turn lanes and tapers, shall be located entirely within the area between the permitee’s property lines extended to the centerline of the roadway. A driveway radius may extend outside of that area only if the adjacent property owner certifies in writing that he will permit such extension.
If the driveway is to be located adjacent to a roadway intersection, the following shall apply:
1. If the intersecting highway is curbed, the point of curvature of the driveway radius shall be at least 20 feet from the point of curvature of the intersecting highway radius.
2. If the intersecting highway is uncurbed, the point of curvature of the driveway radius shall be at least 50 feet from the edge of pavement of the intersecting roadway.
3. When an existing highway or driveway is reconstructed or the requirements in paragraphs (1) or (2) cannot be applied, the driveway radius shall not encroach upon the intersection radius unless such encroachment is physically unavoidable.
A driveway shall not be constructed along the acceleration or deceleration lanes and tapers connecting to interchange ramp terminals unless no other reasonable access point is available.
A driveway shall not enter or cross a clear vision area if another reasonable access point is available.
The design features described in these specifications and illustrated in figure 1 shall be used by the applicant in dimensioning a proposed driveway or driveway system on plans accompanying the Application and Permit Form. The Application and Permit Form, all plans, and applicable fees and deposits must be completed and presented prior to approval and start of work. The dimensions to be used for various driveway design features, shown as a standard with a working range of dimensions, are given in tables 1 to 7. These standard dimensions shall be used unless conditions warrant a deviation. The department may specify particular dimensions to a particular driveway system will accommodate vehicle movements normally expected without creating undue congestion or hazard on the highway or to provide reasonable access. The letters in the following design features refer to features in
Commercial Drive Figure 1:
1. Intersecting angle, A, the clockwise angle from a roadway centerline to a driveway reference line which is the centerline or the edge of the driveway.
2. Driveway width, B, the distance between driveway edges of pavement or edges of the gravel surface measured at the point where the edges of the driveway become parallel, point b in figure 1. If the right-of-way line is so close to the pavement that point b falls on the applicant’s property, then the width of the driveway at the right-of-way line shall be based on the projected driveway width.
3. Entering radius, C, the radius of a driveway edge curve on the right side of a vehicle entering the applicant’s property.
4. Exiting radius, D, the radius of a driveway edge curve on the right side of a vehicle leaving the applicant’s property.
5. Curb ending, E, the length of the height transition of the driveway curb from ground level to full curb height along an uncurbed highway. This curb transition may be 10 feet minimum.
6. Right-turn lane length, F, the length of an auxiliary lane constructed preceding the driveway to accommodate right turn traffic entering the applicant’s property.
7. Right-turn lane width, G, the width edge-to-edge of a right-turn lane, or the width edge-to-edge at the full width of entering and exiting tapers.
8. Entering taper, H, the length of a pavement widening, preceding the driveway for a right-turn lane or taper.
9. Exiting taper, J, the length of a pavement narrowing, following the driveway.
10. Entrance drive width, K, the width of the portion of a divided or a directional driveway that is used by a vehicle entering the applicant’s property.
11. Exit drive width, L, the width of the portion of a divided or a directional driveway that is used by a vehicle leaving the applicant’s property.
12. Island width, M, the edge-to-edge distance between an entrance drive and an exit drive.
13. Island length, N, the distance between ends of the island, measured parallel to the entrance drive.
14. Nose offset, P, the distance between the edge of pavement and the traffic island of a divided or directional driveway.
15. Curb cut, R, the length of the opening along a highway curb for a straight-sided residential driveway.
16. Distance between driveways, S, the inside distance between 2 adjacent driveways measured along a highway right-of-way line.
A permit application for a commercial driveway shall specify the driveway system requested, including the number and type: two-way, one-way, divided, dual service or directional. The road commission may approve the requested system or may require changes in it to insure safe conditions and necessary spacing between driveways, based on anticipated traffic volumes on the driveways and on the roadway, type of traffic to use the driveways, type of roadside development and other operational considerations.
Adjacent property owners may consolidate their commercial driveways by using either a frontage road or a joint driveway system. If the road commission approves such a system, a driveway permit shall be issued to all property owners concerned and shall state that there is an agreement that all properties shall have access to the highway via the frontage road and the joint driveway system.
If the roadway carries one-way traffic, the dimensions may be altered so that the prohibited movements are discouraged. If the driveway system is on the left-hand side of a one-way roadway, the dimensions used shall be based on the same principles as used on right-hand side driveways.
Driveways shall not be constructed over catch basins. Where necessary, the applicant shall relocate the structure to a location where it will not be driven over and still provide the necessary drainage.
The applicant shall provide left-turn lanes, right-turn lanes or tapers as part of a commercial driveway system if the road commission determines that such right-turn lanes or tapers are required to minimize congestion or hazard on the highway caused by vehicles entering the applicant’s driveways. A right-turn-lane shall be preceded by a taper. The design feature dimensions of a right-turn lane and taper shall conform to those given in Commercial Drive Table 1. The surface of the right-turn lane shall be constructed utilizing the same surface material as the mainline roadway.
Left-turn lanes, when constructed, shall provide the necessary transition lengths outlined in AASHTO standards. The entire roadway shall be overlaid, for the length of the turn lane and necessary tapers, with a minimum of 1-1/2" of asphalt. The applicant shall also provide all necessary signing and line striping required to mark the turn lanes.
The design feature dimensions of a two-way commercial driveway shall conform to those given in
Commercial Drive Table 2.
The design feature dimensions of a one-way commercial driveway shall conform to those given in Commercial Drive Table 3.
A divided commercial driveway shall have a curbed island separating the entrance drive and the exit drive. The radii forming the edges on this island shall be designed to accommodate the largest vehicle that will normally use the driveway. The minimum area of the island shall be 50 square feet. The design feature dimensions of a divided commercial driveway shall conform to those given in Commercial Drive Table 4.
To facilitate vehicle movements between a highway and private property when the major vehicle movement at a commercial establishment is approximately parallel to the highway, such as at a service station or drive-in bank, the department may permit dual service driveways. The design feature dimensions of dual service driveways shall conform to those given in Commercial Drive Table 5.
A directional commercial driveway is a special case and the driveway shall be designed individually to facilitate the desired turning movements and to discourage prohibited movements. Radii shall be as approved by the road commission, based on the driveway intersecting angle and on the turning path of the largest vehicle that will normally use the driveway.
Upon completion of the commercial drive construction, the applicant must complete a Completion Notification Form.