National Highway System Monthly Median Traffic Speeds

Monthly 50th percentile median speeds for various US roadway types and vehicles are reported. The Department of Transportation provides this historical data. The dataset was last updated in April 2026.

Use Cases

• Analyze seasonal speed variations by month and roadway_type to identify recurring congestion patterns.
• Compare median speed trends between different vehicle classes to assess road usage and performance.
• Model the relationship between speed percentiles and temporal features like month for forecasting.
• Benchmark historical 50th percentile speeds against current data to measure traffic system changes.

Strengths

• Data covers the US National Highway System, a major road network.
• Provides monthly granularity for tracking trends over time.
• Includes multiple roadway types and vehicle classifications for comparative analysis.

Limitations

• Specific row count, geographic resolution, and sample size are unknown.
• The absence of raw column details limits precise feature understanding.
• Data may have geographic bias if coverage is not uniform across all states.

Provenance

Source

Department of Transportation

Collection Method

null

Time Range

Historical monthly data; specific start date unknown.

Freshness

Updated monthly, with a recent update in April 2026.

Geography

United States National Highway System roads.