Terms & Privacy

What this site is

HCM Calculator (https://hcm-calculator.com) is a browser-based implementation of analysis procedures from the Highway Capacity Manual, 7th Edition. All computation runs locally in your browser through a WebAssembly engine; your inputs are never sent to a server for processing.

A personal project, not a company product

This site is the independent, personal work of Rei Tamaru and Jonathan Riel. It is not affiliated with, endorsed by, or connected to any employer, company, or organization of its authors, and it does not represent the views or products of any such organization. It is likewise not affiliated with the Transportation Research Board or the National Academies, publishers of the Highway Capacity Manual. The HCM itself is a copyrighted publication; this tool implements published procedures but does not reproduce the manual, and you need your own copy of the HCM for the authoritative text, exhibits, and thresholds.

No revenue

This site is free. We collect no revenue from it in any form: no payments, no subscriptions, no advertising, no sponsored content, no affiliate links, and no sale or monetization of user data.

Engineering disclaimer

Results from this calculator are provided for informational and educational purposes. Although the compute engine is validated against the HCM's published example problems, software defects, methodology interpretation differences, and input errors are always possible. Results are not engineering advice, and no professional engineer reviews your analysis through this site. Verify all results independently before relying on them in design, operations, or any decision affecting public safety, and engage a licensed professional engineer where the law or the stakes require one.

No warranty and limitation of liability

The site and its results are provided as is, without warranty of any kind, express or implied, including fitness for a particular purpose. To the maximum extent permitted by law, the authors are not liable for any damages arising from use of this site or reliance on its results.

Privacy, cookies, and analytics

Your analysis inputs and results stay on your device. The site stores a small number of preferences in your browser: your theme choice, your analytics consent choice, and session-scoped run reports that clear when the tab closes. These are functional storage, not tracking.

With your consent, the site uses Google Analytics to count visits and understand which chapters are used, which sets cookies from Google. Analytics loads only after you accept the consent prompt, and declining it disables analytics entirely with no effect on any feature. Google's processing of analytics data is described in Google's own privacy documentation. We do not use any other tracking, and we never see your analysis data.

Open source

The calculator's source code is public in the crosstraffic GitHub organization under its repository licenses. You are welcome to read it, file issues, and contribute. The site's name and logo are not licensed for use in a way that implies endorsement.

Changes and contact

These terms may be updated as the site evolves; the date above reflects the current version. Questions or concerns are welcome as GitHub issues.