Guide
How Traffic Infrastructure Works
A plain-English overview of traffic infrastructure: signals, signs, markings, intersections, crossings, timing, detection, calming, operations, and maintenance.
Topics: traffic systems, signals, signs
Article library
Traffic infrastructure articles
Browse guides to traffic signals, intersections, roundabouts, pedestrian crossings, lane markings, signs, traffic calming, speed management, congestion, work zones, transit priority, and smart traffic systems.
Guide
Traffic Signals Explained
How traffic signals use heads, phases, controllers, detection, timing, cabinets, communications, and maintenance to manage movements.
Topics: traffic signals, controllers, phases
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Signal Timing Explained
What signal timing means, including cycle length, phases, splits, offsets, coordination, pedestrian time, detection, and tradeoffs.
Topics: signal timing, cycle length, phases
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Intersections Explained
How intersections organize turning, crossing, stopping, yielding, signals, signs, markings, pedestrians, cyclists, buses, and sightlines.
Topics: intersections, turning, crossings
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Roundabouts Explained
How roundabouts manage traffic with yield-at-entry operation, central islands, splitter islands, deflection, pedestrian crossings, and lane choice.
Topics: roundabouts, yield control, central island
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Pedestrian Crossings Explained
How crosswalks, refuge islands, curb ramps, signals, flashing beacons, visibility, and timing support pedestrian movement.
Topics: pedestrian crossings, crosswalks, refuge islands
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Accessible Crossings and Curb Ramps
Why accessible crossings need curb ramps, detectable surfaces, pushbuttons, timing, refuge areas, grades, and clear paths.
Topics: accessibility, curb ramps, detectable surfaces
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Lane Markings Explained
How lane lines, arrows, stop bars, crosswalks, bike markings, bus lanes, turn lanes, and pavement symbols guide road users.
Topics: lane markings, arrows, stop bars
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Road Signs Explained
How regulatory, warning, guide, parking, lane-use, school-zone, work-zone, and temporary signs support traffic operations.
Topics: road signs, regulatory signs, warning signs
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Traffic Calming Explained
How speed humps, curb extensions, chicanes, narrowed lanes, raised crossings, mini-roundabouts, and design cues affect traffic speed.
Topics: traffic calming, speed humps, curb extensions
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Speed Management Infrastructure
How posted speeds, design speed, lane width, visibility, traffic calming, enforcement context, and road environment interact.
Topics: speed management, design speed, posted speed
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Vehicle Detection and Traffic Sensors
How loops, cameras, radar, buttons, Bluetooth/Wi-Fi data, counters, and other detection tools support traffic signals and planning.
Topics: vehicle detection, sensors, loops
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Traffic Data and Counts Explained
How traffic counts, turning movement counts, pedestrian counts, speed studies, travel time, and crash data inform planning.
Topics: traffic counts, turning movements, speed studies
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Coordinated Traffic Corridors
What signal coordination means and how offsets, progression, travel speed, side streets, pedestrians, and buses affect corridors.
Topics: signal coordination, offsets, progression
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Congestion Management Explained
How infrastructure, demand, bottlenecks, signal timing, incidents, parking, freight, transit, and land use affect congestion.
Topics: congestion, bottlenecks, incidents
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Bus Lanes and Transit Priority
How bus lanes, queue jumps, signal priority, stops, curb space, enforcement, and road design support transit movement.
Topics: bus lanes, transit priority, queue jumps
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Cycle Lanes and Traffic Design
How bike lanes, protected lanes, crossings, conflict zones, buffers, markings, signals, and intersections affect cycling infrastructure.
Topics: cycle lanes, protected lanes, buffers
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Work Zone Traffic Control
How temporary signs, cones, barriers, lane closures, detours, flagging, signals, and staging protect road users and workers.
Topics: work zones, temporary signs, barriers
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School Zone Traffic Infrastructure
How signs, markings, crossings, speed management, parking rules, bus zones, sidewalks, and visibility support school travel.
Topics: school zones, crossings, speed management
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Streetlighting and Traffic Safety
How lighting, visibility, crossings, intersections, signs, markings, and maintenance connect to traffic safety after dark.
Topics: streetlighting, traffic safety, visibility
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Intersection Lighting and Crosswalks
Why lighting at intersections and crosswalks must consider pedestrians, turning vehicles, glare, pole placement, and visibility.
Topics: intersection lighting, crosswalks, pedestrians
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Smart Traffic Systems Explained
What smart traffic systems can do, including adaptive signals, monitoring, data feeds, incident detection, communications, and controls.
Topics: smart traffic, adaptive signals, monitoring