N.M. Admin. Code § 18.31.6.15

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

Section 18.31.6.15 - TRAFFIC ENGINEERING EVALUATION

A.General: A traffic engineering evaluation shall be required for all proposed access points that are requested along the state highway system, to be submitted with the access permit application (see Paragraph (1) of Subsection D of 18.31.6.14 NMAC). The extent of the traffic engineering evaluation is directly related the scope of the highway improvement under consideration, or to the size and type of land use for which access is requested. In this section, operational performance standards, traffic data requirements and traffic signal considerations are described. Additional information regarding traffic engineering evaluation requisites are provided in Section 15 of the state access management manual. The specific traffic study process that shall be followed to address the traffic engineering evaluation requirement for a land development project are described in 18.31.6.16 NMAC. The criteria that shall be used to determine when speed-change lanes are required or should be considered at existing or proposed access points along the state highway system are defined in 18.31.6.17 NMAC. Design standards applicable to the traffic engineering evaluation are provided in 18.31.6.18 NMAC and are further described in section 18 of the state access management manual.

B.Scope of evaluation: A traffic engineering evaluation shall be required when new or modified access facilities are proposed along a state highway to ensure that the operational characteristics of all state highways are maintained at acceptable levels. The evaluation may include, but is not limited to, roadway and intersection level of service calculations, driveway and intersection location and spacing assessments, traffic signal warrant and systems analyses, roadway and intersection design, and safety analysis. The department shall require a traffic engineering evaluation of access issues for land development projects that request access to a state highway, directly or indirectly, and for highway improvement projects (see Subsection AV of 18.31.6.7 NMAC). The traffic engineering evaluation shall be performed by a registered engineer, authorized under New Mexico Engineering and Surveying Practice Act (Sections 61-23-12 NMSA 1978 through 61-23-13 NMSA 1978).

C.Traffic operational performance: The operational performance of a highway segment, intersection or access facility is described by level of service (LOS). Level of service is a quantitative measure of roadway or intersection operations and vehicle capacity. Level of service standards are defined by access category. level of service (LOS) F shall not be accepted for individual movements.

D.Establishing existing traffic conditions: Engineering evaluations of traffic and roadway conditions on state highways should be based on current traffic count information. The traffic data will be considered current if it is or has been collected within one year of the date that a scoping meeting is held between the permittee and the district traffic engineer, or if otherwise approved for use by the district traffic engineer.

(1) Defining the data collection period: The permittee should recommend the periods for traffic data collection at the traffic analysis scoping meeting held between the permittee and the department district traffic engineer. The periods for traffic data collection may include typical weekday conditions, special traffic conditions, or both.

(2) Typical weekday traffic conditions: Traffic data representing typical weekday conditions should be obtained on Tuesday, Wednesday or Thursday, and may be obtained on Monday or Friday.

(3) Special traffic conditions: Special traffic conditions typically occur from 1900 to 2400 hours and from 0000 to 0600 hours on weekdays, and throughout the day on Saturday and Sunday. The duration of special traffic counts should be based on the activity or event and be sufficient to capture the peak travel condition.

(4) Traffic data for traffic signal warrant analysis: A minimum of 12 hours of traffic count data for a representative day shall be obtained when conducting a traffic signal warrant analysis. Manual intersection turn movement counts shall be conducted for at least eight of the 12 hours. The remaining four hours of data may be obtained using counting equipment on the intersection approaches, or by conducting a 12-hour intersection turn movement count. It is desirable to conduct an eight-hour manual turn movement count supplemented by 24-hour machine counts on each intersection approach when evaluating the need for traffic signal control on a state highway.

E.Design hour volume: Design hour volumes (DHV) should be calculated for the AM peak hour and the PM peak hour of a typical weekday, or for the design hour associated with special traffic conditions. Design hour volume is synonymous with the term peak-hour volume that is used for traffic operations analysis. For land development projects, the DHV should be based on the traffic data collected to establish existing traffic conditions combined with background traffic growth and traffic generated by pertinent site-specific land development. For highway improvement projects, appropriate future year traffic forecasts should be developed to represent the DHV for the facility.

F.Traffic signals: Traffic signals may be warranted at either public or private access locations due to new land development or the redevelopment of an existing property. The installation of traffic signal control shall be preceded by a traffic engineering evaluation that includes detailed analysis of the need for and an assessment of its impact upon the state highway. The engineering evaluation shall be conducted in accordance with the MUTCD, as clarified in sections of the state access management manual, and shall include a traffic signal warrant analysis.

(1) Installation: If the warrant analysis and traffic engineering evaluation indicates that a signal is warranted, the permittee shall be required to provide all of or a portion of the funding for the installation (see Subsection K of 18.31.6.14 NMAC). The funding requirements will be determined by the department.

(2) Traffic signal spacing: The number of traffic signals per mile has a significant influence on travel speed and vehicular delay along a roadway. Acceptable travel speeds and minimal delay occur when sufficient distance and relatively uniform spacing is provided between signals. Traffic signal spacing requirements shall be defined according to the highway functional classification where the intersection is located and shall be more restrictive for higher type roads.

(3) Operations and Maintenance: The electric power supply and maintenance for a signal installation shall be the responsibility of the local governmental agency. A signalization and lighting agreement stating the operation and maintenance responsibilities shall be executed between the department and the local agency prior to installation of the signal. For land development projects, the signalization and lighting agreement shall be the responsibility of the permittee. For highway improvement projects, the signalization and lighting agreement shall be the responsibility of the departments project development engineer.

N.M. Admin. Code § 18.31.6.15

18.31.6.15 NMAC - Rp, 18 NMAC 31.6.12.4 & 18 NMAC 31.6.12.5, 10/15/2001, Adopted by New Mexico Register, Volume XXVIII, Issue 12, June 27, 2017, eff. 6/27/2017