Free WiFi service is now available in most of SEPTA's Broad Street subway stations, SEPTA and Comcast officials announced Thursday.

Four of the 24 stations - including the line's two busiest (City Hall and Fern Rock) - do not have service yet. WiFi service will not be available on trains outside of the stations.

Comcast Corp. installed the service at no charge to SEPTA. The availability of the Internet service coincides with SEPTA's experimental return of all-night weekend service on the Broad Street and Market-Frankford subway lines, which begins at 12:01 a.m. Sunday.

- Paul Nussbaum