The Highway Safety Manual (HSM) is a publication of the American Association of State Highway Transportation Officials. It contains concepts, guidelines, and computational procedures for predicting the safety performance of various highway facilities. [1]
The HSM was published in 2010 and is divided into four sections:
American Association of State Highway and Transportation Officials
The American Association of State Highway and Transportation Officials (AASHTO) is a standards setting body which publishes specifications, test protocols, and guidelines that are used in highway design and construction throughout the United States. Despite its name, the association represents not only highways but air, rail, water, and public transportation as well.
Traffic psychology is a discipline of psychology that studies the relationship between psychological processes and the behavior of road users. In general, traffic psychology aims to apply theoretical aspects of psychology in order to improve traffic mobility by helping to develop and apply crash countermeasures, as well as by guiding desired behaviors through education and the motivation of road users.
Rumble strips are a traffic calming feature to alert inattentive drivers of potential danger, by causing a tactile fuzzy vibration and audible rumbling transmitted through the wheels into the vehicle interior. A rumble strip is applied along the direction of travel following an edgeline or centerline, to alert drivers when they drift from their lane. Rumble strips may also be installed in a series across the direction of travel, to warn drivers of a stop or slowdown ahead, or of an approaching danger spot.
The Manual on Uniform Traffic Control Devices for Streets and Highways is a document issued by the Federal Highway Administration (FHWA) of the United States Department of Transportation (USDOT) to specify the standards by which traffic signs, road surface markings, and signals are designed, installed, and used. In the United States, all traffic control devices must legally conform to these standards. The manual is used by state and local agencies as well as private construction firms to ensure that the traffic control devices they use conform to the national standard. While some state agencies have developed their own sets of standards, including their own MUTCDs, these must substantially conform to the federal MUTCD.
The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two programs, the Federal-aid Highway Program and the Federal Lands Highway Program. Its role had previously been performed by the Office of Road Inquiry, Office of Public Roads and the Bureau of Public Roads.
Pontis is a software application developed to assist in managing highway bridges and other structures. Known as AASHTOWare Bridge Management since version 5.2, Pontis stores bridge inspection and inventory data based on the U.S. Federal Highway Administration (FHWA) National Bridge Inventory system coding guidelines. In addition, the system stores condition data for each of a bridge's structural elements.
Clearview, also known as Clearview Hwy, is the name of a humanist sans-serif typeface family for guide signs used on roads in the United States, Canada, Indonesia, the Philippines, Israel, Brazil and Sri Lanka. It was developed by independent researchers with the help of the Texas Transportation Institute and the Pennsylvania Transportation Institute, under the supervision of the Federal Highway Administration (FHWA). It was once expected to replace the FHWA typefaces in many applications, although newer studies of its effectiveness have called its benefits into question.
Annual average daily traffic, abbreviated AADT, is a measure used primarily in transportation planning, transportation engineering and retail location selection. Traditionally, it is the total volume of vehicle traffic of a highway or road for a year divided by 365 days. AADT is a simple, but useful, measurement of how busy the road is.
The Standard Alphabets For Traffic Control Devices,, is a sans-serif typeface developed by the United States Federal Highway Administration (FHWA). The font is used for road signage in the United States and many other countries around the world. The typefaces were developed to maximize legibility at a distance and at high speed. The typeface has 6 fonts, from narrow to wider strokes:
In the United States, speed limits are set by each state or territory. States have also allowed counties and municipalities to enact typically lower limits. Highway speed limits can range from an urban low of 25 mph (40 km/h) to a rural high of 85 mph (137 km/h). Speed limits are typically posted in increments of five miles per hour (8 km/h). Some states have lower limits for trucks, some also have night and/or minimum speed limits.
Traffic barriers keep vehicles within their roadway and prevent them from colliding with dangerous obstacles such as boulders, sign supports, trees, bridge abutments, buildings, walls, and large storm drains, or from traversing steep (non-recoverable) slopes or entering deep water. They are also installed within medians of divided highways to prevent errant vehicles from entering the opposing carriageway of traffic and help to reduce head-on collisions. Some of these barriers, designed to be struck from either side, are called median barriers. Traffic barriers can also be used to protect vulnerable areas like school yards, pedestrian zones, and fuel tanks from errant vehicles. In pedestrian zones, like school yards, they also prevent children or other pedestrians from running onto the road.
Complete streets is a transportation policy and design approach that requires streets to be planned, designed, operated and maintained to enable safe, convenient and comfortable travel and access for users of all ages and abilities regardless of their mode of transportation. Complete Streets allow for safe travel by those walking, cycling, driving automobiles, riding public transportation, or delivering goods.
Wrong-way driving (WWD), also known as contraflow driving, is the act of driving a motor vehicle against the direction of traffic. It can occur on either one- or two-way roads, as well as in parking lots and parking garages, and may be due to driver inattention or impairment, or because of insufficient or confusing road markings or signage, or a driver from a right-hand traffic country being unaccustomed to driving in a left-hand traffic country, and vice versa. People intentionally drive in the wrong direction because they missed an exit, for thrill-seeking, or as a shortcut.
Trinity Industries Inc. is an American industrial corporation that owns a variety of businesses which provide products and services to the industrial, energy, transportation and construction sectors.
A roadway departure is a type of incident that occurs when a vehicle leaves the roadway. Such incidents can lead to a single-vehicle collision.
The geometric design of roads is the branch of highway engineering concerned with the positioning of the physical elements of the roadway according to standards and constraints. The basic objectives in geometric design are to optimize efficiency and safety while minimizing cost and environmental damage. Geometric design also affects an emerging fifth objective called "livability", which is defined as designing roads to foster broader community goals, including providing access to employment, schools, businesses and residences, accommodate a range of travel modes such as walking, bicycling, transit, and automobiles, and minimizing fuel use, emissions and environmental damage.
A digital billboard is a billboard that displays digital images that are changed by a computer every few seconds. Digital billboards are primarily used for advertising, but they can also serve public service purposes. These are positioned on highly visible, heavy traffic locations such as expressways and major roadways.
The ET-Plus Guardrail system is a guardrail end terminal system manufactured by Trinity Highway Products, based in Dallas, Texas. The ET-Plus was designed at the Texas A&M Transportation Institute and built by Trinity. The end terminal cap absorbs the impact of a crash. The wooden posts break and the guardrail collapses. The end terminal slides along, pushing the guardrail to the side. However, in 2005, Trinity made changes to the ET-Plus without reporting the changes. It was alleged that the Trinity design change caused it to malfunction. A lawsuit under the False Claims Act filed in 2012 against Trinity stated that these changes were causing damages to cars and drivers. Tests have shown that the guardrails act the way they should.
Thomas D. Larson was an American administrator, who was sworn in as the Federal Highway Administrator on August 10, 1989. A native of Pennsylvania, Larson came to the FHWA after a career as a researcher, Professor of Civil Engineering, and administrator at the Pennsylvania State University. He was Pennsylvania's Secretary of Transportation for eight years, and a leader in the American Association of State Highway and Transportation Officials and the Transportation Research Board.
FHWA Office of Safety Highway Safety Manual page https://safety.fhwa.dot.gov/hsm/
Crash Modification Factor Clearing House http://www.cmfclearinghouse.org/