As of this past May, 70% of U.S. residents ages 18 and older access the Internet via high-speed broadband, although the rate of broadband adoption has been sluggish, according to survey results released Monday by the Pew Research Center's Internet and American Life Project.
Just 3% of U.S. residents access the Internet via dial-up, which is unchanged since August 2011, Pew found.
But while the number of people zipping along the "information superhighway" may be high at 70%, the percentage does not constitute a major shift in online behavior. Compared to the 66% of adults who said they had home broadband in April 2012, Monday's results show only "a small but statistically significant rise," the report said.
Access rates were more or less stagnant in previous years, too. In August 2011, 62% of adults had high-speed access. In May 2010, it was 66%.
The report points to several socioeconomic factors to explain the trend toward home broadband access.
"We've consistently found that age, education and household income are among the strongest factors associated with home broadband adoption," said Kathryn Zickuhr, the report's lead author, in a statement.
In keeping with previous research findings, groups with the highest rates of home broadband adoption continue to be college graduates, adults under age 50, adults living in households earning at least $50,000, and white people and adults living in urban or suburban areas, the report said.
The gap in broadband adoption rates between younger and older adults is large: 80% of adults ages 18-29 have high-speed broadband compared to 43% of seniors 65 and older.
The study includes data going as far back as 2000, showing that broadband adoption rates first surpassed dial-up rates between 2004 and 2005.
The study also took a look at smartphones, which have helped to provide an alternative form of home Internet access as their popularity has grown in recent years, authors said.
If the devices are included in the definition of broadband, they are also exacerbating the broadband gap between older and younger people, the report said.
Adding smartphone ownership to the mix, the percentage of young adults with broadband increases to 95%, while the access rate for seniors rises only moderately to 46%.
Smartphones are narrowing the gap, however, between some racial and ethnic groups. While black people and Latinos are less likely to have home broadband than white people, their use of smartphones nearly eliminates that difference, the report said.
Today, 56% of U.S. adults own some kind of smartphone, the report said.
The report is based on data from telephone interviews conducted between April and May of this year, among more than 2,200 adults, Pew said.