N.M. Admin. Code § 18.31.6.18

Current through Register Vol. 35, No. 23, December 10, 2024

Section 18.31.6.18 - ACCESS LOCATION AND DESIGN STANDARDS

The location and design of access points along state highway facilities shall be in accordance with standards established by the department. These standards are defined below and are expounded on in Section 18 of the state access management manual. Where specific design criteria are not provided in 18.31.6.18 NMAC, the design approach should be based on nationally accepted standards and shall be consistent with department specifications.

A.General: The department has developed these standards to provide guidance for the location and design of access points along state highways, specifically for those highways in access categories (provided in Section 18.31.6.10 NMAC). These criteria are based upon established design standards meant to protect public safety, to maintain safe and smooth-flowing traffic operations, and to preserve the intended function of all state highway facilities.

(1) Local standards: Where a local jurisdiction has established more stringent design standards than the department, the local standards should be applied with the concurrence of the department.

(2) Material placed within state rights-of-way: Any materials used within state highway right-of-way shall be subject to approval by the department. Refer to 18.31.6.14 NMAC for additional requirements regarding construction within state highway right-of-way.

B.Access location: Access points should be located along state highways to minimize turning movement conflicts between adjacent access facilities, and to provide adequate separation of conflicts for oncoming motorists. Stopping sight distance and intersection area of influence should be considered in determining access point locations.

(1) Direct access: The number of access points should be limited to one per site unless frontage is adequate and design hour traffic volumes indicate that the operational level of service for a single access is expected to be below the minimum acceptable LOS standards.

(2) Proximity to speed-change lanes: Any part of an access including radius returns shall not be permitted within a speed-change lane, or within 50 feet of either the leading or trailing limits of a speed-change lane.

(3) Interchange proximity: Access shall not be permitted within the access control limits of an interchange, as established by the department's access control determination, or within 50 feet of the leading or trailing edge of the access control limits for the interchange.

(4) Corner clearance: Driveway access should be controlled on both the approach and departure sides of an intersection to maintain adequate corner clearances.

(5) Edge clearance: The location of access points relative to frontage property lines should be based on local requirements. When property frontage is not adequate to comply with local government's edge clearance requirements, shared access should be considered.

C.Access spacing:

(1) Non-developed and developing areas: The spacing of access points in non-developed and developing areas should be based on the access category, the posted speed limit, and the type of access requested (i.e., intersection or driveway). Desired access spacing standards are provided in Section 18 of the state access management manual. An applicant may request a variance to the spacing requirements when physical characteristics of a property preclude the desired spacing.

(2) Developed areas/business districts: In developed or redeveloping areas where existing driveway locations preclude access spacing based on desired standards, new access points should be located to minimize conflicts with existing access points. Access points should be consolidated where possible to provide shared property access.

D.Median openings: New median openings on state highways with non-traversable medians should not be allowed unless a traffic engineering evaluation analyzing all related traffic and safety issues is prepared and approved by the department. Median openings at intersections or full-access driveways should be spaced with a minimum frequency based upon the access category and posted speed of the highway.

E.Selection of design vehicle: The design vehicle should be used to determine the geometric characteristics of a roadside access or median opening, and to define the required design components for the adjacent highway. This vehicle should be the largest vehicle that is expected to access the site on a daily basis. Selection of the design vehicle is subject to the approval of the district traffic engineer.

F.Sight distance: Sight distance at all access locations shall be adequate to provide safe operating conditions for the motoring public. An access permit should not be issued unless adequate stopping sight distances are provided for motorists passing the access, and adequate entering and crossing sight distances are provided for motorists using the access. The permittee shall maintain adequate, unobstructed sight distance in both directions from the access. Any potentially obstructing objects such as but not limited to advertising signs, structures, trees and bushes, shall be designed, placed and maintained at a height not to interfere with the sight distances needed by any vehicle using the access. Roadway reconstruction may be required to provide adequate sight distance.

G.Access horizontal alignment: The access centerline should be perpendicular to the state highway centerline and extend tangentially for a minimum distance of 40 feet beyond the near-side edge line. An acute angle between 75 degrees and 90 degrees may be permitted if significant physical constraints exist. Acute angles less than 75 degrees shall require special approval of the department.

H.Access radius: The access radius should be designed to accommodate the design vehicle expected to use the access on a daily basis. Access radii apply to driveways that are not urban section driveway cuts.

I.Driveway width: The width of a driveway should be measured exclusive of radii or tapers. Driveway widths should vary by design vehicle. All two-way driveways should accommodate a concurrent entering and exiting design vehicle, including the design vehicle's off-tracking.

J.Access connection depth: The access connection depth should be designed to facilitate the movement of vehicles off the highway to prevent the queuing of vehicles on the traveled way. An access shall not be approved for parking areas that require backing maneuvers within state highway right-of-way. All off-street parking areas must include on-site maneuvering areas and aisles to permit vehicles to enter and exit the site in forward drive without hesitation.

K.Speed change lanes: Design specifications for speed change lanes are provided in Section 18 of the state access management manual. Schematic illustrations of speed-change lanes are included in the appendix of the state access management manual.

(1) Deceleration lanes: Deceleration lanes typically consist of three components: transition taper, deceleration distance, and queue storage. The length of the lane should allow a vehicle to come to a comfortable stop prior to reaching the end of the expected queue in the lane.

(2) Acceleration lanes: Acceleration lanes should consist of a full-width lane and a transition taper. Acceleration lanes should be designed so that a turning vehicle will reach a speed between seventy-five and eighty percent of the highway posted speed at the point where the full-width lane ends and the transition taper begins.

(3) Shoulders: Where shoulders are present along a roadway and speed change lanes are required, the shoulders should be continued along the speed change lanes. A minimum shoulder width of four feet should be provided adjacent to speed change lanes.

(4) Bicycle lane width: When a right-turn deceleration lane or acceleration lane is required on a roadway with designated bicycle lanes, a five foot lane width (seven foot desirable) should be provided between the outside travel lane and the speed-change lane.

(5) Grade adjustment: Adjustments should be made to the speed change lane lengths based on the roadway grade.

(6) Truck design: If a speed-change lane is designed for a site with five or more large trucks during the design hour, a combination truck design vehicle should be used as the design vehicle.

(7) Pavement: The speed change lane pavement section should be full depth and match the pavement section design of the adjacent roadway. All pavement designs require approval by the department.

L.Median design for turn lane installation: Medians should be designed to accommodate the largest design vehicle anticipated to use the access, and may provide either partial or full access to a site. Where a single left-turn lane is necessary along a state highway, a minimum median width of 16 feet should be provided. Positive channelization should be provided for all median openings. Median paving should be full depth and match the pavement section design of the existing roadway. The installation of a median opening should not reduce the conveyance or storage capacity of the median, pertinent to its drainage function within the highway section.

M.Setbacks: Improvements on public or private property adjacent to the right-of-way should be located so that parking, stopping, and maneuvering of vehicles within the highway right-of-way will not occur.

N.Access vertical alignment: The vertical alignment of all access locations should be designed to minimize vehicle bounce and prevent high-centering of vehicles with a maximum clearance of four inches. The maximum grade for a driveway should be ten percent for a low volume residential driveway and eight percent for all other access locations. Steeper access drives require special department approval. A level area (maximum two percent grade) 20 feet in length should be provided at each access to ensure proper sight distance from the access.

O.Roadside safety: Careful consideration shall be given to the roadside clear zone. The permittee shall provide adequate clear zones. The roadside clear zone should be designed per the AASHTO roadside design guide and applicable department standards.

P.Non-motorized considerations: Access designs should provide for the safe movement of all right-of-way users, including but not limited to pedestrians, bicyclists, equestrian and the handicapped. Where non-motorized facilities cross an access point, such as bicycle trails, appropriate modifications should be made to maintain safe operations for both facilities.

(1) Sidewalks: Sidewalks should be constructed along urban arterial and collector state highways. Sidewalks are required where they exist on adjacent properties to maintain consistency along the highway facility. Sidewalk widths should match existing adjacent sidewalk widths, but in any case shall conform to all federal, state, and local regulations and ordinances.

(2) Bicycle facilities: Bicycle facilities along urban arterials and collectors should be constructed in accordance with the AASHTO guide for the development of bicycle facilities. Bicycle facilities should only be signed where designated by the state or local jurisdiction, with approval of the department.

(3) ADA: Non-motorized facilities shall be designed in accordance with the Americans with Disabilities Act and applicable department standards. Curb ramps shall be provided on urban sections where sidewalk and curb returns exist.

Q.Lighting: Where lighting is required at an access point, the lighting design shall comply with Department and AASHTO standards and the Night Sky Protection Act (Sections 74-12-1 NMSA 1978 through 74-12-11 NMSA 1978). The lighting design shall use full cut-off fixtures, and be consistent with AD 226, roadway lighting.

(1) Signalized access: Illumination shall be provided at all signalized intersections in accordance with AASHTO's an informational guide to roadway lighting or as otherwise approved by the department.

(2) Site illumination: Light beams from on-site lighting systems shall not be directed toward oncoming traffic along the adjacent roadway(s). All site illumination shall be constructed outside of the state highway right-of-way and outside of the roadside clear zone.

R.Drainage: Adequate drainage within state highway right-of-way shall be maintained at all access locations. Drainage of roadside ditches shall not be altered or impeded, and the applicant shall provide suitable and approved drainage structures as required by the department. All site drainage shall be collected prior to entering state highway right-of-way. Site drainage shall not be permitted to drain into state right-of-way without written approval of the department. Drainage mitigation design shall be in accordance with administrative memorandum 221, drainage design criteria, and the department drainage manual. Access permit applicants shall submit drainage analysis documentation to the department prior to changing site drainage conditions.

S.Right-of-way fencing: Driveways shall not be permitted through an existing right-of-way fence, the continuation of which is necessary for the safety of the traveling public, unless the applicant first agrees in writing to construct and maintain a gate or a cattle guard and additional fence in good repair and to keep the gate closed to livestock. The department shall determine whether a gate or cattle guard is required. All new fencing along a state highway shall be constructed so that clear sight triangles are provided for ingressing or egressing vehicles. This may require an offset from the right-of-way line to meet the minimum clear site triangles, on a case by case basis.

T.Mailboxes: Mailboxes installed within the state highway right-of-way shall be constructed in conformance with the rules and regulations of the U.S. Postal service and the design standards of the department. AASHTO's a guide for erecting mailboxes on highways, should also be used for the location and design of mailbox installations.

U. Utilities: All utilities located within the state highway right-of-way shall comply with the department's utility accommodations Policy and 17.4.2. NMAC.

V.Environmental review: As may be required by law.

N.M. Admin. Code § 18.31.6.18

18.31.6.18 NMAC - Rp, 18 NMAC 31.6.11.3 through 18 NMAC 31.6.11.5; 18 NMAC 31.6.12.1 through 18 NMAC 31.6.12.3; 18 NMAC 31.6.12.6; 18 NMAC 31.6.12.7.7 through 18 NMAC 31.6.12.7.11; 18 NMAC 31.6.12.9; 18 NMAC 31.6.12.10; 18 NMAC 31.6.12.12; 18 NMAC 31.6.12.13; 18 NMAC 31.6.12.14.2 through 18 NMAC 31.6.12.14.4; 18 NMAC 31.6.12.14.6; 18 NMAC 31.6.12.14.7; 18 NMAC 31.6.12.14.10; 18 NMAC 31.6.12.15, 10/15/2001, Adopted by New Mexico Register, Volume XXVIII, Issue 12, June 27, 2017, eff. 6/27/2017