2023 NFPA 502 Standard - Current Edition
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  • Description

    Tackle today’s structural protection and emergency readiness challenges to reduce hazards and help safeguard lives.

    Introducing your updated fire and life safety sidekick: NFPA® 502, Standard for Road Tunnels, Bridges, and Other Limited Access Highways—the international standard for limited access highways, road tunnels, bridges, elevated highways, depressed highways, and roadways that are located beneath air-right structures. With comprehensive provisions for ventilation, means of egress, electrical systems, standpipe and water supply, and traffic control and communications, NFPA 502 is essential for designers, engineers, architects, authorities having jurisdictions (AHJs), and state and federal regulators.

    The 2023 update also includes:

    • New Annex D that provides guidance on controlling smoke formation in tunnels with critical velocity calculation methods
    • Recategorization of tunnels to reduce the number of categories
    • New requirements covering safety features required for Category A tunnels
    • Updates to Annex G to incorporate the latest developments and hazards for alternative fuel vehicle technology
    • Updated requirements to address recognition of various non-listed systems
    • Added references to other standards for the use of alternative time-temperature curves when testing passive fire protection materials
    • Updated design objectives 
    • Updated requirements to remove unenforceable terms, update references, and make other editorial corrections
  • Table of Contents (2023 Current Edition)

    NFPA® 502 Standard for Road Tunnels, Bridges, and Other Limited Access Highways, 2023 Edition

    Chapter 1 Administration
    1.1 Scope.
    1.2 Purpose.
    1.3 Application.
    1.4 Retroactivity.
    1.5 Equivalency.
    1.6 Units.
    Chapter 2 Referenced Publications
    2.1 General.
    2.2 NFPA Publications.
    2.3 Other Publications.
    2.4 References for Extracts in Mandatory Sections.
    Chapter 3 Definitions
    3.1 General.
    3.2 NFPA Official Definitions.
    3.3 General Definitions.
    Chapter 4 General Requirements
    4.1 Level of Fire Protection.
    4.2 Safeguards During Construction.
    4.3 Fire Protection and Fire-Life Safety Factors.
    4.4 Emergency Response Plan.
    4.5 Emergency Communications.
    4.6 Signage.
    4.7 Commissioning and Integrated Testing.
    4.8 Noncombustible Material.
    4.9 Structural Anchorage.
    Chapter 5 Limited Access Highways
    5.1 General.
    5.2 Traffic Control.
    5.3 Fire Apparatus.
    5.4 Protection of Structural Elements.
    5.5 Incident Detection. (Reserved)
    5.6 Fire Hydrants. (Reserved)
    5.7 Drainage.
    Chapter 6 Bridges and Elevated Highways
    6.1 General.
    6.2 Application.
    6.3 Protection of Structural Elements.
    6.4 Incident Detection.
    6.5 Traffic Control.
    6.6 Standpipe, Fire Hydrants, and Water Supply.
    6.7 Portable Fire Extinguishers.
    6.8 Drainage.
    6.9 Hazardous Locations.
    6.10 Control of Hazardous Materials.
    6.11 Joints Between Structural Elements.
    Chapter 7 Road Tunnels
    7.1 General.
    7.2 Application.
    7.3 Protection of Structural Elements.
    7.4 Fire Alarm and Detection.
    7.5 Emergency Communications Systems — Two-Way Radio Communication Enhancement System.
    7.6 Tunnel Closure and Traffic Control.
    7.7 Fire Apparatus. (Reserved)
    7.8 Standpipe, Fire Hydrants, and Water Supply.
    7.9 Portable Fire Extinguishers.
    7.10 Fixed Water-Based Firefighting Systems.
    7.11 Emergency Ventilation.
    7.12 Tunnel Drainage System.
    7.13 Alternative Fuels. (Reserved)
    7.14 Control of Hazardous Materials.
    7.15 Flammable and Combustible Environmental Hazards.
    7.16 Means of Egress.
    7.17 Acceptance Test.
    Chapter 8 Roadways Beneath Air-Right Structures
    8.1 General.
    8.2 Application.
    8.3 Traffic Control.
    8.4 Protection of Structure.
    8.5 Emergency Ventilation.
    8.6 Drainage System.
    8.7 Control of Hazardous Materials.
    8.8 Emergency Response Plan.
    8.9 Standpipe, Fire Hydrants, and Water Supply.
    8.10 Acceptance Test.
    Chapter 9 Fixed Water-Based Firefighting Systems
    9.1 General.
    9.2 Design Objectives.
    9.3 Water Supply.
    9.4 Performance Evaluation.
    9.5 Tunnel Parameters.
    9.6 System Design and Installation Documentation.
    9.7 Engineering Design Requirements.
    Chapter 10 Standpipe Systems
    10.1 General.
    10.2 Water Supply.
    10.3 Fire Department Connections.
    10.4 Hose Connections.
    10.5 Fire Pumps.
    10.6 Identification Signs.
    Chapter 11 Emergency Ventilation
    11.1 General.
    11.2 Smoke Control.
    11.3 Design Objectives.
    11.4 Basis of Design.
    11.5 Fans.
    11.6 Dampers.
    11.7 Sound Attenuators.
    11.8 Controls.
    11.9 Flammable and Combustible Liquids Intrusion.
    Chapter 12 Electrical Systems
    12.1 General.
    12.2 Wiring Methods.
    12.3 Installation Methods.
    12.4 Emergency Power.
    12.5 Reliability.
    12.6 Emergency Lighting.
    12.7 Security Plan.
    12.8 Wayfinding Lighting.
    Chapter 13 Emergency Response
    13.1 General.
    13.2 Emergency Incidents.
    13.3 Emergency Response Plan.
    13.4 Participating Agencies.
    13.5 Operations Control Center (OCC).
    13.6 Liaisons.
    13.7 Emergency.
    13.8 Training, Exercises, Drills, and Critiques.
    13.9 Records.
    Chapter 14 Regulated and Unregulated Cargoes
    14.1 General.
    Chapter 15 Periodic Testing
    15.1 General.
    Annex A Explanatory Material
    Annex B Tenable Environment
    Annex C Temperature and Velocity Criteria
    Annex D Smoke Control
    Annex E Fixed Water-Based Systems in Road Tunnels
    Annex F Emergency Response Plan Outline
    Annex G Alternative Fuels
    Annex H The Memorial Tunnel Fire Ventilation Test Program
    Annex I Tunnel Ventilation System Concepts
    Annex J Control of Road Tunnel Emergency Ventilation Systems
    Annex K Fire Apparatus
    Annex L Motorist Education
    Annex M Automatic Fire Detection Systems
    Annex N Autonomous Vehicles
    Annex O Informational References
  • Prior Editions

    2020 Edition

    Be prepared to meet the modern fire protection and life safety challenges of road bridges, tunnels, and limited access highways with the newly revised NFPA 502.

    Arm yourself with a powerful resource for addressing risks and implementing appropriate safety systems with NFPA 502, Standard for Road Tunnels, Bridges, and Other Limited Access Highways. The 2020 edition offers the latest requirements for construction, operation, maintenance, and fire protection of limited-access highways, tunnels, bridges, elevated highways, and air right structures.

    This international NFPA standard covers everything from emergency systems and response to traffic control and communications. You will find comprehensive provisions for ventilation, means of egress, electrical systems, standpipe and water supply, control of hazardous materials, and other critical information on mitigating dangers and safeguarding lives.

    NFPA 502, 2020 edition, offers the most current requirements for structural protection and emergency readiness for road tunnels and bridges.

    An essential tool for designers, engineers, architects, AHJs, and state and federal regulators, NFPA 502 is updated to account for the most current industry best practices and technological developments. The revised edition offers several impactful edits and additions, including:

    • Updates to general requirements, to clarify that protection methods described assume a single fire event.
    • Updates in section 6.11 as an analysis is required to be performed on joints of non-conventional and non-grid connections.
    • Further explanations for Fixed-water-based fire-fighting systems (FFFS) throughout the code, as well as in several annex materials.
    • Updates in Chapter 13 for the section on Operations Control Centers (OCCs).
    • A new requirement for structural fire protection material per Subsection 7.3.4.
    • New references to NFPA 72®, National Fire Alarm and Signaling Code®, in Chapter 7 for automatic fire detection systems.

    Upgrade to the most current edition of NFPA 502.

    Be confident that you are working with cutting-edge information and requirements for limited-access highways, road tunnels, and bridges for improved public safety and compliance. Order your copy of NFPA 502, Standard for Road Tunnels, Bridges, and Other Limited Access Highways, today.

    2017 Edition

    NFPA 502 revisions and a new mandate for integrated testing help you improve the fire protection and life safety of today's road tunnels and bridges.

    From emergency egress to communications issues, limited-access highways, tunnels, bridges, elevated highways, and air right structures present a host of unique fire protection and life safety challenges. The 2017 edition of NFPA 502, Standard for Road Tunnels, Bridges, and Other Limited Access Highways provides designers, engineers, AHJs, and state and federal regulators with the latest guidelines for the construction, operation, maintenance, and fire protection of these venues to mitigate hazards, maintain structural integrity, and protect lives.

    This important international Standard also covers traffic control, standpipe and water supply, control of hazardous materials, emergency ventilation, electrical systems, and emergency response.

    Designers, engineers, architects, and AHJs will work more confidently to address risks and implement appropriate safety systems with this edition.

    • Added guidance for conducting an engineering analysis includes a revised list of considerations to be taken into account, along with more guidance in the Annexes.
    • Integrated testing on fire protection, life safety, and emergency systems is now required in accordance with NFPA 4, Standard for Integrated Fire Protection and Life Safety System Testing.
    • Modified requirements for the structural protection of bridges will assist designers, engineers, architects, and AHJs.
    • Annex B includes guidance on establishing noise levels in order to maintain a minimum level of speech intelligibility through the emergency communication system.
    • The constant K1 used in the critical velocity equation of Annex D has been modified and is no longer a constant for heat release rates (HRR) less than or equal to 100 MW.
    • Annex E presents new information regarding the effects of fire suppression on HRR and tunnel ventilation.
    • New Annex M adds guidance on the use of automatic fire detection systems in road tunnels.

    Apply the latest requirements to safeguard the public on limited-access highways, road tunnels, and bridges. (Softbound, 72 pp., 2017)


    Interested in other editions of NFPA 502? Use the drop down menu above to select the edition year you need.

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