Thanks for that. The reason as to why you have 3Mbps (actually a little bit less than that) is due to the line quality. It looks like you have a long telephone line back to the central office, past 2.5 miles. That is assuming your line does not have a problem that is actually degrading the signal further than attenuation caused by long copper runs does.
If you'd like to see if you can get more, try connecting your modem to the NID and getting the same statistics. If they look better you can then look into getting a home run installed - that is, a dedicated unfiltered line for just the modem, and the rest of your home is filtered out at a central point. For more information on what a NID is, see this page: http://www.dslreports.com/faq/1317
Failing that, you'd an ask Verizon to both confirm your line length and also send a tech out to see if they can either condition your line a bit or find a shorter path to the CO.
