“Anytime, Anywhere Road Weather Information”

The Federal Highway Administration 

(FHWA) Road Weather Management 

Program (RWMP) recently completed 

a study titled Human Factors Analysis 

of Road Weather Advisory and Control 

Information (Publication No. FHWAJPO-10-053). The goal of the study 

was to evaluate the current state of 

practice in communicating weatherrelated traffi c advisory and control 

information to the public, and to recommend ways to improve those practices. 

The research came up with a set 

of guidelines for communicating 

road weather information that meets 

the needs of drivers and travelers 

under different weather conditions and 

travel scenarios. 

Background 

The last decade has seen tremendous 

growth in both the amount of available 

weather information, and the methods 

by which this information can be disseminated to travelers. This growth 

includes weather gathering devices 

(sensors, satellites), models and forecasting tools for predicting weather 

conditions, and electronic devices used 

by drivers (e.g., Internet, in-vehicle 

devices, roadway signage). 

Improvements in both the type, volume, 

and quality of road weather information, 

however, do not automatically lead to 

better decisions by drivers. Specifi cally, 

unless the content, format, and timing 

of road weather information is consistent with what travelers need, want, 

and will use, such information may not 

be useful and – in certain situations – 

may even lead to reduced mobility, as 

well as unsafe driving behaviors. 

To address this issue, the Federal 

Highway Administration’s (FHWA) 

Road Weather Management Program 

(RWMP) initiated a project to identify 

traveler requirements for road weather 

information, review and evaluate the 

state of the practice in communicating 

road weather information, and recommend ways to improve those practices. 

Current Practices 

and Research 

An important aspect of determining traveler requirements 

for weather information is 

obtaining detailed information about road weather 

messages and dissemination methods currently in 

use and/or documented 

in literature. The study 

found the following are the 

current practices: 

Weather Messages: Existing 

weather advisory and control 

messages that are used by state 

transportation agencies and other 

providers of weather information, 

include messages on precipitation, 

visibility, wind, and extreme weather 

events such as thunderstorms, 

hurricanes, tornadoes, fl oods, etc. 

Dissemination Strategies: Messages are posted on the road and 

disseminated through traveler 

information systems such as 

kiosks, websites, in-vehicle navigation systems, dynamic message 

signs (DMS’s), Highway Advisory 

Radio (HAR), cellular phones, 

511, and other road weather 

information portals.

Road Weather Information for Travelers 

Improving Road Weather Messages and Dissemination Methods 
“Anytime, Anywhere Road Weather Information”

Pub #: FHWA-JPO-11-001

U.S. Department of Transportation

Road Weather Management

1200 New Jersey Avenue, E86-205

Washington, DC 20590

Roemer M. Alfelor

202-366-9242

E-mail. roemer.alfelor@dot.gov

http://ops.fhwa.dot.gov/Weather/index.asp

Study Recommendations

The study recommendations on 

the content of weather messages 

and how that information should be 

disseminated focused on providing 

end users with a decision/design tool 

organized around key driver behaviors 

and refl ective of key weather events. 

The general form of the decision/

design tool is shown in the fi gure to 

the right. End users work through 

a short series of questions to 

identify the weather event and 

corresponding mobility impacts and 

traveler decisions that the weather 

message should support. 

Based on these inputs, the tool provides recommended dissemination 

methods and guidance on appropriate 

road weather messages. 

Overall, the study produced a number of guidelines to disseminate road 

weather advisory and control information to travelers in a manner that is 

understandable, useful, and effective. 

Specifi cally, thirty (30) detailed guidelines for road weather advisory and 

control information were developed, 

refl ecting relevant literature and 

best practices for topics, including 

the following:

Message content, length, and 

structure;

Design of fonts, colors, icons, 

and alerts;

Display of map, weather, and 

traffi c information; and 

How to communicate weather 

event timeframe, urgency, and 

likelihood.

This approach ensures the information 

is organized around traveler information needs and driving decisions. 

Specifi c guidance is also provided 

for the range of dissemination methods (DMS, HAR, 511, etc.) associated 

with road weather information.

Benefi ts of Improved 

Information 

Improvements in the presentation 

and timing of road weather advisory 

and control information for travelers 

will result in a number of benefi ts 

including the following: 

Effective and timely dissemination of road weather information by 

individual transportation agencies 

and others;

Weather messages that are more 

useful, understandable, accurate, 

and specifi c;

Informed pre-trip decisions by 

travelers regarding routes, modes, 

and departure times; 

Decisions by travelers that are 

more likely to refl ect actual conditions and lead to safer driving 

behaviors; and

A more consistent approach to 

the content and delivery of road 

weather information across cities, 

states, and regions. 

To download a copy of the full 

report, go to http://ntl.bts.gov/lib/

33000/33000/33047/rev_final_hf_

analysis_road_weather.pdf.

All photos and graphs in the document 

are courtesy of the Road Weather 

Management Program.

Weather

Events

Traveler

Decisions

Dissemination

Methods Guidelines

What are the Key 

Mobility Impacts?

What are the Traveler

Decisions to be made?

What are the appropriate

Dissemination Methods?

For Example: For Example: For Example:

Reduced traction

Congestion

Poor visibility

Road closures

Expect and plan for delays

Use alternative route

Change travel modes

Drive with greater caution?

Change their driving behavior

Make safety-related preparations

Cancel their trip

DMS

HAR

511

Navigation devices

Cell Phones

Kiosks

Web sites

Decision/Design Tool

Road Weather Information for Travelers 

Improving Road Weather Messages and Dissemination Methods