[jsweojtj]

There are a couple of reasons that this isn't the explanation.

To pick one, the random data selection in the blog post showed data from October 2015 -- Feb 2016, and this Caltrain link appears to show the bridge work starting Feb 26th, 2016.

So, no the just-so story doesn't appear to be just-so.

[mattcaywood]

The data is very much consistent with the bridge work hypothesis. The website indicates a series of bridges are being replaced. Starting 9/28/15 with Tilton Ave. and proceeding northward to Monte Diablo Ave then Santa Inez Ave.