ANAHEIM

For about 10 months, motorists will not be able to use the Santa Ana Freeway onramp at Katella Avenue. The closure this week comes as part of a construction project to make the Katella overpass an underpass. The closure of the southbound onramp allows the work to accelerate, transportation officials said. To enter the southbound Santa Ana Freeway from Katella, drivers will be detoured onto Manchester Avenue for the onramp south of Orangewood Avenue. The construction is part of the $1.1-billion Santa Ana Freeway project begun in December 1996 and expected to be completed next year.