Traffic Data

General
Traffic data is used in a variety of project development situations, such as selection of design criteria and pavement design. For the purpose of this chapter, “traffic data” is defined as whatever data is required to complete the associated design activity. TxDOT’s
Transportation Planning and Programming Manual
provides information related to traffic data and requires TxDOT to maintain a single source of all traffic data reported to the commission, Legislature, governor and the public.
Federal Requirements
  1. 23 CFR §420.105(b)
    – Requires state departments of transportation to provide data that support the FHWA’s responsibilities to Congress and the public.
  2. 23 CFR §500.203(b)
    – Requires traffic monitoring systems to comply with the American Association of State Highway and Transportation Officials (AASHTO) Guidelines for Traffic Data Programs and the FHWA
    Traffic Monitoring Guide
    , and to be consistent with the FHWA
    Highway Performance Monitoring System Field Manual
    .
  3. 23 CFR Part 625
    – Designates standards and policies that are acceptable to FHWA for application in the geometric and structural design of highways.
    1. Projects on the national highway system (NHS) must adequately serve existing and planned future traffic of the highway in a manner that is conducive to safety, durability and economy of maintenance.
    2. Federally funded projects off the NHS are to be designed and constructed in accordance with state laws, regulations, directives, safety standards and design standards.
  4. AASHTO’s A Policy on Geometric Design of Highways and Streets is a document accepted by FHWA as satisfactory for use on federally funded projects. In Texas, FHWA accepts TxDOT’s
    Roadway Design Manual
    for use on federally funded projects and for compliance with AASHTO policy.
State Requirements
  1. 43 TAC §15.56
    – Requires projects to be designed in accordance with TxDOT procedures, standards, and guidelines.
Required Practices
The
LGPM Guide
provides guidance for the LG and TxDOT in the use of traffic data. In general, for all projects with state or federal funds on the state highway system, the LG must use traffic data furnished by TxDOT. For projects with state or federal funds off the state highway system, the LG may request traffic data from TxDOT or use other data, including its own, if approved by TxDOT.