AADT = annual average daily traffic
AAR = Association of American Railroads
AASHTO = American Association of State Highway and Transportation Officials
AAWS = active advance warning sign
ADA = Americans with Disabilities Act
AREMA = American Railway Engineering and Maintenance-of-Way Association
ASLRRA = American Short Line and Regional Railroad Association
BRT = Bus Rapid Transit
C&M = construction and maintenance
CFR = Code of Federal Regulations
Crossing(s) = At-Grade Highway-Rail Crossing(s)
CSD = Clear Storage Distance
DOT = Department of Transportation
DSRC = Dedicated Short-Range Communications
FAPG = Federal-Aid Policy Guide
FARS = Fatal Accident Reporting System
FAST Act = Fixing America's Surface Transportation Act
FHWA = Federal Highway Administration
FMCSA = Federal Motor Carrier Safety Administration
FRA = Federal Railroad Administration
FTA = Federal Transit Administration
GPS = Global Positioning System
HSIP = Highway Safety Improvement
ICC = Interstate Commerce Commission
IEEE = Institute of Electrical and Electronics Engineers
ISTEA = Intermodal Surface Transportation Efficiency Act
ITE = Institute of Transportation Engineers
ITS = Intelligent Transportation Systems
LED = light emitting diode
LRT = light-rail transit
LRV = light-rail vehicles
MAP-21 = Moving Ahead for Progress in the 21st Century Act
MCSAP = Motor Carrier Safety Assistance Program
MPH or mph = miles per hour
MTB = Materials Transportation Bureau
MTCD = Minimum Track Clearance Distance
MUTCD = Manual on Uniform Traffic Control Devices
NCDOT = North Carolina Department of Transportation
NCHRP = National Cooperative Highway Research Program
NCUTCD = National Committee on Uniform Traffic Control Devices
NHS = National Highway System
NHTSA = National Highway Traffic Safety Administration
NSRT = Nationwide Significant Risk Threshold
NTD = National Transit Database
NTSB = National Transportation Safety Board
O&M = Operations and Maintenance
OLI = Operation Lifesaver Incorporated
PHMSA = Pipeline and Hazardous Materials Safety Administration
PL = Public Law
PROWAG = [Draft] Proposed Right-of-Way Accessibility Guidelines
QZRI = Quiet Zone Risk Index
ROW = right-of-way
SAFETEA-LU = Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users
SHSP = Strategic Highway Safety Plan
SMIS = Safety Management Information System
STAA = Surface Transportation Assistance Act
STB = Surface Transportation Board
STP = Surface Transportation Program
TEA-21 = Transportation Equity Act for the 21st Century
TCRP = Transit Cooperative Research Program
TMS = Traffic Management System
TRB = Transportation Research Board
TTC = Temporary Traffic Control
TTCI = Transportation Technology Center, Inc.
TWG = Technical Working Group
U.S.C. = United States Code
USDOT = United States Department of Transportation
UVC = Uniform Vehicle Code
WBAPS = Web Based Accident Prediction System