With three long rides a week, you certainly sound like you are well on track for a solid base - plenty of time out from the race if its next year too.

When I am doing a base-training ride, or active recovery ride, my average is about 26kph if mostly flat, and about 22-24kph if there are hills.

My road race average is about 28-30kph (most of our courses have hills and are about 35-40km long - though last Saturdays was 66km and this Saturdays is 52).
I TT on a 20-25km course at around 32kph (though this is still improving as I get better at it).

So it sounds to me (when I think about what I do) like you are setting a good tempo.