BOISE - Idaho drivers will see the first change to interstate speed limits in nearly two decades beginning July 1 with an increase on most rural stretches of interstate across southern Idaho, the Idaho Transportation Department announced.

For the majority of interstates 15, 84 and 86, the speed limit will increase to 80 mph for vehicle traffic and 70 mph for trucks. The speed limit in the urban areas of the Treasure Valley, between Caldwell and east Boise, as well as through Pocatello and Idaho Falls, will remain at 65 mph.

State forces will work throughout July 1 to implement the speed changes on all sections of the interstate. Some areas of interstate could be delayed until July 2, depending on the pace of work and other complications such as weather.

There are no changes to the 65 mph speed limit on Interstate 90 through northern Idaho at this time.

This is the first statewide increase to the interstate speed limit since an increase from 65 to 75 mph in 1996. The speed limit was raised from 55 mph to 65 mph in the 1980s.

The increased speed limit, approved by the Idaho Legislature during the 2014 session, increases the maximum speed limits on interstate highways to 80 mph for vehicles and 70 mph for trucks as deemed appropriate by ITD.

The law was signed by Gov. Butch Otter on March 18 and becomes effective July 1. The 80-mph speed limit is authorized "if the department completes an engineering and traffic study on the interstate highway and concludes that the increase is in the public interest," the law reads.

AAA Idaho expressed concerns on raising speed limits on interstate and state roads in testimony, news releases and guest opinions during the 2014 legislative session. The concerns focused on the perceived need to raise limits in the first place, and the potential traffic safety implications speed limit changes could have on interstate routes and state highways.

"AAA is unaware how the state system could have been analyzed so completely in such a short time," a AAA press release states. "AAA is concerned that the rapid switchover itself could pose safety risks for highway users. AAA is also deeply concerned about the process and will look into the matter."