3G data traffic has doubled every year, even with Clear entering the picture.
Jan 2010 saw about 6,000 TB of daily 3G traffic. By Jan 2011, it hit 12,000 TB/day. I have not checked this year, but I bet it is close to 24,000 TB/day.
Reducing tower strain will take creativity in addition to increasing capacity. The strain is good in that it forces innovation.