Charter Communications confirmed Wednesday that it will impose new bandwidth caps on subscribers. In addition, Time Warner, which is currently testing a pay-per-download plan in Beaumont, Texas, said Wednesday it intends to expand that test soon to four additional cities.

As of Feb. 9, Charter--the fourth-largest cable company in the U.S.-- will limit customers who purchase speeds of up to 15 Mbps to 100 gigabytes a month, while those who purchase up to 25 Mbps will be capped at 250 gigabytes. People who pay for speeds up of to 60 Mbps will not face any limits. News of the caps was first reported by BroadbandReports.com.

A Charter spokesperson said the limits will not affect many subscribers. "More than 99% of current Charter Internet customers use less bandwidth than the threshold allows and therefore will not need to change their surfing habits in any manner," the spokesperson said.

Time Warner spokesperson Alex Dudley said the company is still choosing which cities to expand its pay-as-you-go program to. "We're looking for diverse geography and diverse demographics," he said. "What we've learned from the Beaumont trial is that we can make this work. Now we need to see if it will scale to larger, more urban environments."

New Time Warner subscribers in Beaumont are offered a choice of four plans that allow them to download set amounts each month: 5, 10, 20 or 40 Gigabytes. Those who go over their allotment are charged extra. When Time Warner expands to other cities, it will likely add other tiers of service at both the low and high end, Dudley said.

Other companies also have recently moved to limit bandwidth use. Comcast said last August it would impose caps of 250 gigabytes, while AT&T last November began imposing limits of between 20 and 150 GB per month in Reno, Nev.

But some consumer advocates worry that these types of limits will hinder the growth of the Web. Derek Turner, research director of Free Press, said that at least some Web users are likely to curtail their use rather than worry about overage charges like those to be imposed by Time Warner, the second-largest U.S. cable company.

Turner also discounted Charter's claim that fewer than 1% of users exceed the proposed caps. Even if that's currently the case, average bandwidth consumption is likely to continue to surge as more content migrates online. Already in the last several years, consumption has grown tremendously, thanks to online video at sites like YouTube, iTunes and Netflix. "Today's average user, two or three years ago, would have been considered excessive," Turner said.

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