Section 1A.01 Purpose of Traffic Control DevicesSupport: Show
02 Traffic control devices notify road users of regulations and provide warning and guidance needed for the uniform and efficient operation of all elements of the traffic stream in a manner intended to minimize the occurrences of crashes. Standard: Support: Section 1A.02 Principles of Traffic Control DevicesSupport: Guidance:
03 Design, placement, operation, maintenance, and uniformity are aspects that should be carefully considered in order to maximize the ability of a traffic control device to meet the five requirements listed in the previous paragraph. Vehicle speed should be carefully considered as an element that governs the design, operation, placement, and location of various traffic control devices. Support: Guidance: 06 The proper use of traffic control devices should provide the reasonable and prudent road user with the information necessary to efficiently and lawfully use the streets, highways, pedestrian facilities, and bikeways. Support: Section 1A.03 Design of Traffic Control DevicesGuidance: 02 Aspects of a device's standard design should be modified only if there is a demonstrated need. Support: Option: Section 1A.04 Placement and Operation of Traffic Control DevicesGuidance: 02 Traffic control devices should be placed and operated in a uniform and consistent manner. 03 Unnecessary traffic control devices should be removed. The fact that a device is in good physical condition should not be a basis for deferring needed removal or change. Section 1A.05 Maintenance of Traffic Control DevicesGuidance: 02 Physical maintenance of traffic control devices should be performed to retain the legibility and visibility of the device, and to retain the proper functioning of the device. Support: Section 1A.06 Uniformity of Traffic Control DevicesSupport: Section 1A.07 Responsibility for Traffic Control DevicesStandard: 02 23 CFR 655.603 also states that traffic control devices on all streets, highways, bikeways, and private roads open to public travel in each State shall be in substantial conformance with standards issued or endorsed by the Federal Highway Administrator. Support: 04 The "Uniform Vehicle Code" (see Section 1A.11) has the following provision in Section 15-104 for the adoption of a uniform manual:
05 All States have officially adopted the National MUTCD either in its entirety, with supplemental provisions, or as a separate published document. Guidance: Support: Guidance: Section 1A.08 Authority for Placement of Traffic Control DevicesStandard: 02 When the public agency or the official having jurisdiction over a street or highway or, in the case of private roads open to public travel, the private owner or private official having jurisdiction, has granted proper authority, others such as contractors and public utility companies shall be permitted to install temporary traffic control devices in temporary traffic control zones. Such traffic control devices shall conform with the Standards of this Manual. 03 All regulatory traffic control devices shall be supported by laws, ordinances, or regulations. Support: 05 Although some highway design features, such as curbs, median barriers, guardrails, speed humps or tables, and textured pavement, have a significant impact on traffic operations and safety, they are not considered to be traffic control devices and provisions regarding their design and use are generally not included in this Manual. 06 Certain types of signs and other devices that do not have any traffic control purpose are sometimes placed within the highway right-of-way by or with the permission of the public agency or the official having jurisdiction over the street or highway. Most of these signs and other devices are not intended for use by road users in general, and their message is only important to individuals who have been instructed in their meanings. These signs and other devices are not considered to be traffic control devices and provisions regarding their design and use are not included in this Manual. Among these signs and other devices are the following:
Standard: Guidance: Section 1A.09 Engineering Study and Engineering JudgmentSupport: Standard: Guidance: 04 Jurisdictions, or owners of private roads open to public travel, with responsibility for traffic control that do not have engineers on their staffs who are trained and/or experienced in traffic control devices should seek engineering assistance from others, such as the State transportation agency, their county, a nearby large city, or a traffic engineering consultant. Support: Section 1A.10 Interpretations, Experimentations, Changes, and Interim ApprovalsStandard: Support: Standard: Option: Support: 06 An interpretation includes a consideration of the application and operation of standard traffic control devices, official meanings of standard traffic control devices, or the variations from standard device designs. Guidance:
Support: 09 A request for permission to experiment will be considered only when submitted by the public agency or toll facility operator responsible for the operation of the road or street on which the experiment is to take place. For a private road open to public travel, the request will be considered only if it is submitted by the private owner or private official having jurisdiction. 10 A diagram indicating the process for experimenting with traffic control devices is shown in Figure 1A-1. Figure 1A-1 Process for Requesting and Conducting Experimentations for New Traffic Control Devices Guidance:
Support: Guidance:
Support: 15 Interim approval is considered based on the results of successful experimentation, results of analytical or laboratory studies, and/or review of non-U.S. experience with a traffic control device or application. Interim approval considerations include an assessment of relative risks, benefits, costs, impacts, and other factors. 16 Interim approval allows for optional use of a traffic control device or application and does not create a new mandate or recommendation for use. Interim approval includes conditions that jurisdictions agree to comply with in order to use the traffic control device or application until an official rulemaking action has occurred. Standard: Guidance:
Option: Guidance: 21 A local jurisdiction, toll facility operator, or owner of a private road open to public travel that is requesting permission to experiment or permission to use a device or application under an interim approval should first check for any State laws and/or directives covering the application of the MUTCD provisions that might exist in their State. Option: Support: Figure 1A-2 Process for Incorporating New Traffic Control Devices into the MUTCD 24 For additional information concerning interpretations, experimentation, changes, or interim approvals, visit the MUTCD website at http://mutcd.fhwa.dot.gov. Section 1A.11 Relation to Other PublicationsStandard: Support: 03 For information about the publications mentioned in Paragraph 1, visit the Federal Highway Administration's MUTCD website at http://mutcd.fhwa.dot.gov, or write to the FHWA, 1200 New Jersey Avenue, SE, HOTO, Washington, DC 20590. 04 Other publications that are useful sources of information with respect to the use of this Manual are listed in this paragraph. See Addresses in this Manual for ordering information for the following publications (later editions might also be available as useful sources of information):
Section 1A.12 Color CodeSupport: 02 The two colors for which general meanings have not yet been assigned are being reserved for future applications that will be determined only by FHWA after consultation with the States, the engineering community, and the general public. The meanings described in this Section are of a general nature. More specific assignments of colors are given in the individual Parts of this Manual relating to each class of devices. Standard:
Section 1A.13 Definitions of Headings, Words, and Phrases in this ManualStandard:
02 Unless otherwise defined in this Section, or in other Parts of this Manual, words or phrases shall have the meaning(s) as defined in the most recent editions of the "Uniform Vehicle Code," "AASHTO Transportation Glossary (Highway Definitions)," and other publications mentioned in Section 1A.11. 03 The following words and phrases, when used in this Manual, shall have the following meanings:
Section 1A.14 Meanings of Acronyms and Abbreviations in this ManualStandard:
Section 1A.15 Abbreviations Used on Traffic Control DevicesStandard:
*This abbreviation shall not be used for any application other than the name of a roadway. 02 When the word messages shown in Table 1A-2 need to be abbreviated on a portable changeable message sign, the abbreviations shown in Table 1A-2 shall be used. Unless indicated by an asterisk, these abbreviations shall only be used on portable changeable message signs. Table 1A-2. Abbreviations that Shall be Used Only on Portable Changeable Message Signs
* This abbreviation, when accompanied by the prompt word, may be used on traffic control devices other than portable message signs. Guidance: Standard:
Guidance: 06 Except as otherwise provided in Table 1A-1 or 1A-2 or unless necessary to avoid confusion, periods, commas, apostrophes, question marks, ampersands, and other punctuation marks or characters that are not letters or numerals should not be used in any abbreviation. Back to Top What element is the sensing device that detects the condition of the process variable?Primary sensing element (PSE) – It is a device directly sensing the process variable and translating the sensed quantity into an analog representation (electrical voltage, current, resistance, mechanical force, or motion etc.
Which term refers to a group of instruments connected together to perform a specific control task?Instrument Loop. a control system in which one or more instruments are connected together to perform a task. Control Loop.
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