RATP is the public transportation company in Paris. It manages an impressive network of more than 200 subway stations, more than 200 km of subway tunnels, as well as countless bus lines. A modern company, RATP pursues a policy of openness. Part of this policy is to make transit information available to the general population. The goal is to offer the data to analysts that can identify new ways to use transit feed data.
A very recent and bold move has been to even make available the real-time information (arrival time or wait time) for the buses and subways. It is not possible to make the real-time data sets available directly, but as an API that can be consumed as part of the programmable web. This API is based on SOAP, but it is only a matter of time until a REST equivalent version will be ready for use.
For the moment, the data is given under a fair use license, which is very generous. The upper limit is 30 million requests per month. That is 3 followed by seven zeroes. I haven’t tested the API yet. The only limitation of the real-time part is the update time. Data is written in the database every 5 minutes. During rush hours, there are subways or buses which have higher frequencies. We can talk of a quasi real-time API. This is still great. By using mathematical models, one can compensate the missing part and extrapolate the near accurate value.
Good job, RATP guys.