Altoona City Council is considering a new ordinance that would prohibit the use of truck engine brakes… sometimes referred to as “jake brakes” along 31st Street below Mill Run. The brakes.. made by Jacobs Vehicle Systems… slow large diesel trucks going down hills by releasing cylinder compression earlier than normal so they don’t propel the truck forward. They work well, but they are very noisy, and all that noise has resulted in a lot of complaints from people living in that area. But before Altoona can do anything, studies have to be done, because according to PennDOT, a jurisdiction can’t prohibit jake brakes on a downgrade steeper than 4%; an off-ramp from a 55 mph or faster highway; in a reduced-gear zone; where there has been a runaway truck crash in the last three years or a pattern of rear-end crashes by trucks; or on any stretch where the speed limit is 55 mph or more. If such an ordinance could be enacted, then there would be other issues such as enforcement. Altoona Police say they lack the manpower to stake out an area just to catch jake brake violators, and if they did have that manpower, they would most likely dedicate it to speeding enforcement.