The old N7 carried respectable levels of traffic before it was completely replaced from 2000-2010. The opening of the Nenagh Bypass in 2000 reduced traffic on the route from around 11k vehicles to 6k within two years, and at Morrette (between Portlaoise and Monasterevin) from 18k to only 2,300 when the new section opened in late 2004.
Note that this graph is longer being maintained, since most of the points are bypassed. See the M7 Counts page for current information.