# 往来 / Traffic art

Traffic art is licensed under GPL-3.0-or-later. Its corresponding editable source is index.html, art.js and models.js in this directory; no build step is required.

models.js is copied unmodified from movsim/traffic-simulation-de, commit 96d39348dc20b363cdafb1bce37822a3873302a9:
https://github.com/movsim/traffic-simulation-de/blob/96d39348dc20b363cdafb1bce37822a3873302a9/js/models.js

Upstream authors: Martin Treiber and the movsim contributors. See the upstream repository for history and attribution. License text: LICENSE (GPL v3).

art.js and index.html: original artwork, integration and renderer, 2026. The deterministic IDM acceleration calculation is actually used at every simulation step. Roads are parameterized by arc length; car positions use bounded integration to prevent overlaps. This is a visual metaphor, not a physical model of Worker capacity or a prediction.

Live mode uses only /api/stats/traffic. It never substitutes historical hourly submission counts or simulated traffic when measurements are unavailable. Demo mode is explicitly marked 試走 and needs no API. Counts map to a maximum of 110 symbolic vehicles, and median noncached successful correction duration maps to desired speed. Low-volume samples are not used to vary speed. Failed corrections are counted as activity, not interpreted as a measured queue.

Backend telemetry is independently implemented in workers/traffic.mjs. Before production use, apply workers/traffic-schema.sql to D1 and deploy the Worker. No historical backfill. Real operational tests should use a separate preview environment to avoid polluting measurements.