<P> Twenty rockslides occurred along the Walden Ridge section (miles 341--346) of the eastern plateau in 1968 alone, prompting various remedial measures throughout the 1970s, including the employment of rock buttresses, gabion walls, and horizontal drains . A minor rockslide shut down the right lane of westbound I - 40 at mile 343 on May 6, 2013 . </P> <P> An area very prone to rockslides is the Pigeon River Gorge, especially in the vicinity of the Tennessee--North Carolina state line . Throughout the 1970s, this stretch of I - 40 was repeatedly shut down by rockslides, sometimes for several weeks at a time . In the late 1970s and early 1980s, TDOT dug over 24,000 feet (7,300 m) of horizontal drains, blasted out large volumes of unstable rocks, and installed massive mesh catchment fences . Nevertheless, rockslides in 1985 and 1997 again forced the closure of I - 40 in the Pigeon River Gorge for several weeks . Additional stabilization measures were implemented, including the blasting of loose rock, the installation of rock bolts, and the construction of a better drainage system . In spite of these measures, another massive rock slide occurred in the Pigeon River Gorge on October 26, 2009, blocking all lanes just across the border at North Carolina mile 3 . The section was closed to traffic in both directions until April 25, 2010 . On January 31, 2012, the westbound lanes of I - 40 were closed because of a rockslide near the North Carolina border . Traffic was detoured along I - 26 and I - 81 and reopened a few months later . </P> <P> Sinkholes are a consistent issue along highways in East Tennessee . One particularly problematic stretch is a section of I - 40 between miles 365 and 367 in Loudon County, which is underlain by cavernous rock strata . In the 1970s and 1980s, TDOT employed numerous stabilization measures in this area, including backfilling existing sinkholes with limestone, collapsing potential sinkholes, and paving roadside ditches to prevent surface water from seeping into the volatile soil . </P> <Table> <Tr> <Td> </Td> <Td> This section needs to be updated . Please update this article to reflect recent events or newly available information . (April 2016) </Td> </Tr> </Table>

Directions to interstate 40 east from my location