Roads

Roads are engineered surfaces that enable the passage of vehicles, pedestrians, cyclists, and other forms of traffic between destinations. They form a core element of transportation infrastructure and are typically composed of a paving surface, subbase, drainage, and accompanying features such as signage, markings, guardrails, and right of way.

Road networks vary by purpose and setting. Local roads connect neighborhoods, arterial roads carry higher-volume traffic between regions, collectors link local streets to arterials, and highways or expressways are designed for high-speed, long-distance travel. Roads may be paved or unpaved and can include toll sections, bridges, and tunnels. Urban streets balance mobility with access, while rural roads emphasize connectivity.

Road construction has ancient roots, with cartways and linkages in many civilizations. Roman roads standardized routes; in the modern era, paving materials advanced from cobbles to asphalt and concrete surfaces. Design practices incorporate features such as proper grades, sight distance, drainage, and cross-sectional width to accommodate safety and efficiency.

Roads are built and maintained by government authorities at national, regional, and local levels. Funding comes from taxes, fuel levies, tolls, and user fees. Maintenance includes resurfacing, patching, and structural rehabilitation. Traffic management uses signs, markings, signals, and roundabouts to organize flow and reduce conflicts at intersections.

Roads influence economic activity, land use, and access to services. They also pose environmental and safety challenges, including emissions, habitat fragmentation, noise, and pedestrian-vehicle collisions. Road design increasingly emphasizes safety, accessibility for non-motorized users, and sustainable practices, such as stormwater management and material recycling.