The 109 terror case that the TMPD boss and JR officials constantly references is named after the HIkari 109 bullet train that was threatened with a bomb in the original 1975 Bullet Train movie. The Hikari train is one of the original 1964 Shinkansen trains still in service on the Tokaido to San'yo lines. Before it was part of the Shinkansen service, the Hikari was an express train until 1958. It was considered the fastest train in Shinkansen line until Nozomi trains in 1992.
There is a character named Chiba. Sonny Chiba starred in the original Bullet Train in 1975.
The Wilhelm scream makes an appearance at 44:12.