A lot of variables combine to make up these hub scores, but the biggest thing I found was that once I began to publish at least one new hub almost every day - at least 5 or 6 a week- then my hub score and my author score both rose steadily.
Another phenomenon I found early is that the hubs in my collection will never all be 100 at once - they will never all even be 80 at once. There is a range of scores on a continuum and as the hubs rotate in "hotness" (interest) and sustained traffic, the scores go up and down.
Also, use wonder wheel and Google keyword tool to find the words most likely to be searched for your topics and use the words in titles and tags. Once I had a hub go down to 1 and climb up to 100 once I changed the title.
Participating in the HubTrail project is really drawing a lot of traffic. At least three Hubbers purchased websites to promote the group. Look in the forum about it and see if you can make some hubs for Travel.