Like Google, MapQuest entered the vernacular as a verb. As in: I mapquested it. The AOL-owned online map service is still the top site of its kind, but that position is threatened by Google Maps, which is, um, en route to surpass it.

Caution: More bad puns likely.

Hitwise’s vice president of research, Heather Hopkins, beat me off the starting line with the puns, anyway, with her revelation at the Hitwise blog that Google Maps was "making inroads."

But it worse than that, if the last six months are an indicator. During that time period, MapQuest appears to have accidentally shut off cruise control and is losing speed quickly. Though traffic to MapQuest was steady year-over-year, the last half of 2007 saw a 20 percent drop.

Meanwhile, Google Maps, with year-over-year traffic up 135 percent, enjoyed a seven percent increase during the past six months. This throttled down MapQuest’s lead over Google Maps significantly, falling from 429 percent more visits a year ago to just 126 percent more visits.

Yahoo and Live Local? Well, Yahoo Maps took a turn and is headed south, to the tune of a seven percent drop over the past year. Live Local’s trucking along at 3-4 percent of visits, but going straight doesn’t mean you’re going anywhere.

Don’t be too alarmed for MapQuest, though. It’s still hogging half the road, by attracting over 50 percent of the mapquesting public. Google Maps, despite growth, is still only at 22 percent, or nine percent more than Yahoo.

Hopkins suggests that Google’s aggressive promotion of Google Maps – search result embeds and sponsored search results have helped drive the spike in traffic. She says Google Maps received 19 percent of its search traffic from paid listings, compared to MapQuest’s 10 percent.