I have a bike computer which tracks average speed. It's typically about 14.8 to 15 mph. A typical cruising speeds is anything between 16 and 18 mph depending on grade and wind. If wind is unfavorable, that will drop to the 12 to 14 range. The distance is 6.9 miles which typically takes about 28 to 30 minutes with lights and whatnot.

My best average speed was over 16, rarely is it below 14.

Bike is a Breezer Uptown with NuVinci drive, dynamo powered lights on, 1.75 in tires pumped to about 60 psi with liners and a big fat saddle bag on the back.