Though MapQuest remains the clear leader in map websites with a market share of half of US visits on Jan. 5, Google Maps has been on the ascent, receiving some 22% of US visits to Maps as of last week, according to Hitwise's Heather Hopkins, writes MarketingCharts.

Whereas a year ago MapQuest's lead over Google Maps in US visits consisted of 429% more visits, that lead has now shrunk to 126% more visits (a 50% market share vs. 22% for Google Maps), she writes.

Yahoo Maps and MSN's Local Live are third and fourth, respectively, with 13% and nearly 4% of US visits.

Other map-website-related data, according to Hitwise:

• US visits to map websites are up 10% year over year.
• MapQuest's traffic remained flat for the year.
• Google Maps traffic was up 135% in the past year.
• Google sends more traffic to Google Maps than to MapQuest, a trend that began in March 2007 - and not attributable to an in increase in internet searches for "google maps."
• The query "mapquest" still receives nearly 10 times the search-query volume as "google maps."
• In the past four weeks some 19% of Google Maps was from paid search listings, compared with MapQuest's 10%.