traffic is a Python library and CLI tool for processing, analyzing, and visualizing air traffic data. It ingests trajectory data from multiple sources including OpenSky Network (via REST/Trino), FlightRadar24, Eurocontrol (DDR, AIXM), FAA, and local ADS-B decoders. The core abstractions are `Flight` (single trajectory) and `Traffic` (collection) built on pandas DataFrames, with extensive methods for cleaning, resampling, filtering, geometric operations, navigation event detection (landing, go-around, holding patterns), performance estimation (fuel flow, emissions), and clustering. The library provides a declarative lazy evaluation pipeline (`LazyTraffic`) that chains operations before a single `.eval()` call, enabling efficient parallel processing. It also offers visualization backends for Matplotlib, Altair, Leaflet, and Plotly, and includes a Vue.js/Deck.gl plugin (Tangram) for real-time landing alignment in a web dashboard.