Strategies & Concepts
Collaboration & Coordination refers to collaboration between agencies or groups, collecting and using data, managing planned events, incident response & recovery, and land use.
Transportation systems management and operations (TSMO) agreements and policies are the fundamental frameworks that establish how organizations can coordinate effectively with one another on data, infrastructure, operations, equipment, and maintenance sharing.
Interagency coordination for corridor management refers to the methods and policies that enable participating agencies and jurisdictions to operate a corridor, or primary route, jointly and effectively.
Data helps drive decision making and measure the performance of transportation strategies. Agencies can source certain types of data from WSDOT, other agencies, and the private sector.
Emergency management coordination includes collaboration between transportation agencies, transit providers, emergency management, and incident responders during major regional natural disasters.
Instant tow is the immediate dispatch of a tow truck to an incident scene or location of a vehicle or debris blocking a lane so that disabled vehicles can be cleared quickly.
A special or planned event generates a significant increase in people and traffic that impacts the transportation system. Special & Planned event management is a coordinated approach to understand the characteristics of the event, how the event will affect transportation operations, and plan and manage a response to mitigate the impacts.
Traffic impact analysis (TIA) and mitigation planning are specialized engineering studies that forecast the transportation impacts of proposed real estate developments. They support in proposing strategies that can eliminate or reduce the projected impacts.
Traffic Incident Management (TIM) restores traffic flow as safely and quickly as possible following a roadway incident. Through planning and coordination, each of the collaborating agencies can focus on what they do best. State patrol can focus on law enforcement. Fire can focus on health and safety. DOT can focus on traffic control and getting traffic going again.
Traffic management centers (TMCs) are the control centers where municipal or regional transportation operations are coordinated. They support agency coordination and collaboration by collecting various functions within a single location, which allows for a more holistic, system-wide management of regional transportation.
Operations & supporting infrastructure refers to features and enhancements made to roads, roadsides, and transportation facilities that support the movement of people and goods across a transportation network. It includes concepts like Intelligent Transportation Systems (ITS), as well as road and roadside treatments for safety, congestion, or accommodating multiple modes or travel.
Active traffic management (ATM) includes a broad range of strategies for managing traffic dynamically based on current or expected conditions in order to improve the efficiency and safety of the transportation system. ATM strategies include ramp metering, variable speed limits, queue warning, and traveler information systems.
Dynamic lane assignment strategies repurpose road space based on current or expected demand conditions in order to improve the efficiency and safety of the transportation system. Dynamic lane assignment strategies include reversible lanes on highways and arterials, merge (or junction) control on highway ramps, and part-time highway shoulder use.
Automated speed enforcement (ASE) and red light running (RLR) enforcement use cameras to detect traffic law infractions and provide photo or video documentation of the vehicle or driver violating the law. These automated programs enforce speed limits and traffic signal compliance to improve safety and reduce congestion.
Intersection conflict and trail conflict warning systems are traffic control devices that provide road users with a real-time, dynamic warning of vehicles or pedestrians that are approaching or waiting to enter an intersection or crossing.
Parallel route usage and improvements manage traffic shifting from congested roads to underutilized roads, in order to reduce congestion and create route efficiencies.
Ramp closures are the temporary, part-time (for specific parts of the day), or permanent closure on highway entrance or exit ramps. Ramps are typically closed where interchanges are spaced closely together, regular congestion occurs on the highway, a high-collision rate occurs at the ramp, or on ramps with compromised visibility.
Ramp metering is an active traffic management (ATM) strategy that uses traffic signals at freeway on-ramps to control the number of vehicles entering the freeway to keep vehicles moving more efficiently.
Reversible lanes allow agencies to switch the direction of traffic flow during certain times and conditions. They are typically used during peak commuting hours to add capacity in one direction.
Traffic detectors are a critical part of any intelligent transportation system. They collect data about the current traffic conditions so that transportation management and operations decisions can be made.
Traffic incident management (TIM) operations includes the process to quickly detect, verify, respond, manage and clear traffic incidents with the appropriate personnel and equipment. This can improve safety for responders as well as reduce the likelihood of secondary collisions and congestion resulting from the incident.
Transit service planning is used to determine what type of transit service to provide, where to provide it, how much, and when. Planning is tailored to the needs of a particular location and helps develop safe and reliable travel options. Transit operations implements the transit service developed during planning.
Variable speed limits (VSL) is an active traffic management (ATM) strategy that uses dynamic speed limit signs to slow traffic before and through adverse conditions on the freeway to improve safety and keep traffic moving efficiently.
Wrong-way driver detection uses sensors on freeway off-ramps to detect vehicles driving in the wrong direction. The system alerts the driver of their mistake, warns nearby travelers, informs agency staff at a central traffic management center of the need to monitor the situation, and notifies law enforcement so that they can prevent a collision.
As a subset of operations & supporting infrastructure, this category includes strategies related to signals and signalization.
Adaptive signals change traffic signal timings based on current traffic conditions. Using hardware, adaptive signals measure the traffic conditions of vehicles, bicyclists, and pedestrians and then utilize software to make timing changes based on the real-time data.
Emergency vehicle preemption (EVP) interrupts normal traffic signal timing to provide a green light to approaching emergency vehicles so that they can pass through intersections to get to emergencies safely and quickly.
Freight (or truck) signal priority (FSP) provides extra green light time so that a heavy truck can move through a traffic signal without stopping.
Planned event or incident signal timing synchronizes groups of traffic signals to favor traffic entering and exiting a special event venue or area in order to minimize congestion. It can also be used to divert traffic around an unplanned event, such as an incident or a regionwide evacuation.
Proactive signal timing review and optimization uses actual traffic performance data to operate and manage traffic signals. This strategy can help improve safety, reduce vehicle delays, and help more finely target maintenance activities.
Signal timing review and optimization synchronizes groups of traffic signals so that vehicles on a primary route can travel through multiple traffic signals without stopping. It can also reduce vehicle wait times at individual intersections by adjusting the length of green lights to match demand.
Traffic signals are an essential, cost-effective tool to manage the movement of traffic and provide solutions to a variety of mobility, safety, and system management goals. However, traffic signals are sometimes an unnecessary expense that can add to collisions, congestion, and delay.
Traffic signal priority and preemption settings modify the traffic signal timing and give priority to specific vehicle types, such as buses, light rail, streetcars, trucks, emergency vehicles, or trains.
Transit signal priority (TSP) makes it more likely that the light is green when a transit vehicle reaches a signalized intersection. This strategy reduces travel times for transit vehicles by avoiding the need to stop and start at signalized intersections.
Physical design elements includes strategies or concepts that require altering the physical environment in a temporary or permanent manner to help improve access, flow, or reduce transportation cost in a substantial manner.
Access management allows agencies to manage vehicle access points, like driveways and intersections, to help road users safely and efficiently access desired locations like residences and businesses.
Channelization and delineation are design elements that can separate directions of traffic, restrict certain movements, or direct traffic to a particular location.
Low-cost safety enhancements are part of a systemic application of road and roadside treatments that can improve safety at intersections and along many miles of road. Enhancements can range from maintenance to safety features.
Pedestrian facilities are the public right-of-way spaces that are used by people on foot to get from place to place. Improvements to pedestrian facilities include new crosswalk designs for increased safety, curb bulb-outs to reduce the distance it takes to cross a roadway, curb ramps for accessibility, and signal timing improvements that make pedestrians easier for drivers to see at intersections.
A road diet changes roadway usage by replacing some of the typical traffic lanes to make space for other uses like bicycle lanes, sidewalks, or parking.
A roundabout is a type of circular intersection without traffic signals or stop signs, where drivers travel counterclockwise around a center island. When entering the roundabout, drivers yield to existing traffic, then enter the intersection and exit in their desired direction.
Conducting a safety analysis and applying effective countermeasures are crucial in decreasing the number of collisions, reducing congestion, and maintaining the efficiency of the transportation system.
Signs help regulate traffic flow and provide valuable information to road users in order to encourage safe and efficient travel.
Speed management techniques encourage people to use safe speeds while driving. Managing vehicle speeds reduces the number and severity of collisions and increases the efficiency of traffic flow.
Traffic calming reduces vehicle speeds by using roadway design elements, like roundabouts, narrowed roads and speed humps. Traffic calming supports the livability and vitality of residential and commercial areas by improving the safety, mobility, and comfort for all road users, with special care taken for pedestrians and bicyclists.
Turn lanes are dedicated lanes for left and right turning vehicles
Also known as demand management, this category focuses on understanding how people make their transportation decisions and helping people use the infrastructure in place for transit, ridesharing, walking, biking and telework. It also guides the design of our transportation infrastructure so that alternatives to driving are naturally encouraged and our systems are better balanced. We will continue to add articles as this category of strategies evolves.
Active parking management strategies use new parking technology with flexible pricing methods to better utilize the available parking inventory.
High occupancy toll (HOT) lanes are a type of managed lane reserved for single-occupant vehicles that pay a toll and high-occupancy vehicles (HOV) that access the lane for free. HOT lanes use electronic tolling and variable pricing to manage demand in the lanes in order to maintain a speed advantage over the adjacent general purpose freeway lanes.
Trip reduction ordinances include different types of regulations or measures to help mitigate congestion. Typically, there are three forms: restrictions or requirements for developers, employer trip reduction programs, and/or forming transportation management districts and associations.
Also known as commute trip reduction these specific strategies support employers and employees reduce the number of drive-alone or single occupancy trips made during peak commute hours. We will continue to add articles as this category of strategies evolves.
Agencies and employers can provide incentives to employees that encourage them to make travel changes that include choosing another transportation mode, shifting the time that they travel, and selecting alternative routes.
Employers can encourage employees to walk or bike to work by providing on-site facilities to improve convenience for these commute alternatives.
Road freight delivery refers to moving goods over roads by commercial vehicles. It includes topics about Road Freight Transportation, Transporting Freight by Truck, Truck Freight to distinguish it from rail freight services. We will continue to add articles as this category of strategies evolves.
Truck size and weight restrictions are used to preserve the condition of roadways. The Federal Highway Administration sets the standards for truck size and weight, and states enforce them on the Interstate highway system.
Truck lane designations and restrictions help to reduce collisions or congestion by separating or restricting trucks into designated lanes.
Weigh-in-motion (WIM) systems measure the weight of trucks while they are moving in order to identify which vehicles are overweight, so that weight overload penalties can be enforced. The underweight vehicles can bypass the weigh station, while overweight vehicles are directed to another location for additional weighing.
Giving information to travelers in route so they can plan trips or adjust routes due to congestion, incidents, or unsafe conditions.
Highway advisory radio (HAR) transmits audio traveler information messages via radio to travelers within range of the signal. Roadside signs inform travelers of the radio frequency and often use flashing lights to alert travelers of advisory messages.
When a roadway detour to a parallel route is needed, it is necessary to communicate the detour clearly to travelers, as well as consider the transportation safety and efficiency needs on the parallel/detour route.
Queue warnings inform drivers about stopped or slow traffic ahead to provide vehicles more time to slow down safely. Queue warning systems use real-time traffic detection to identify queues and roadside variable message signs (VMS) to display the warnings.
Road weather information systems (RWIS) monitor local roadway and weather condition information and alert an agency and the traveling public about inclement weather conditions. It can be highly customized to the specific weather conditions and detection needs of a given location.
Providing travelers with pre-trip and real-time information about travel times and potential delays can help them make alternate routing and timing decisions to avoid congestion.
Traveler information services use personal, connected devices to provide travelers with real-time and customizable information that is relevant to their specific travel needs. This can include location-based information about delays, incidents, weather-related messages, travel times, emergency alerts, route guidance, and more.
Variable message signs (VMS) are electronic roadside signs used to post traveler information messages to inform drivers of incidents, travel times, detours, special events, and other useful road conditions or travel information.
Work zone & construction strategies support keeping traffic moving and work areas safe during construction projects.
A transportation management plan (TMP) describes how an agency will address the impact of a project on road users during construction.
Funding additional or improved transit service can mitigate the impacts of construction. Typically, funding helps to add services to compensate for transit reductions caused by construction activity or to encourage travelers to use transit running on parallel routes.
Intelligent Transportation Systems (ITS) in work zones encompass a broad range of technologies aimed at enhancing work zone safety and mobility. Strategies may include variable message signs, automated speed enforcement, incident management, providing traveler information, and more.
Also known as Cooperative & Automated Transportation, Automated & Connected Vehicles describes technologies that allow for communication to or between vehicles as well as topics like self-driving cars, innovative communications, and future technologies. We will continue to add articles as this category of strategies evolves.
Automated or driverless truck platooning is one truck following closely behind another using sensors and automated driving technology. Long-haul trucks that follow 40 or 50-feet apart during highway travel save fuel and reduce emissions.
Cooperative automated transportation (CAT), including autonomous and connected vehicles, is an evolving field within transportation.
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