and watercraft, have damaged the highway and rail systems, and have
 restricted the movement of cargo and personnel particularly during day-light
 hours. They have created construction problems and delays,
 ??ed interruptions in the flow of men and supplies, caused a
 great loss of work-hours, and forced North Vietnam to tie up large
 numbers of people in air defense and in the repair of LOCs.
 Communist countermeasures in North Vietnam and Laos have included
 diversification of the means of transport to include greater use
 of inland waterways and porter trails, construction of alternate
 reads, and of multiple bypasses at important bridges. A number
 of truck parks and vehicle pulloffs for quick convoy dispersal
 have been built. These measures have increased the ability of the
 Communists to cope with the effects of air attacks, although at a
 considerable cost and effort. While infiltrating personnel have
 suffered casualties as a result of air strikes in North Vietnam
 and Laos, there is little firm evidence on the extent of these
 casualties.* Units and personnel moving to South Vietnam have been
 forced to move under cover of darkness, slowing their movement and
 subjecting them to the rigors of the trail for longer periods.
 * The representative of the Assistant Chief of Staff, Intelligence,
 USAF, reserves his position on this sentence.
 -18-
 
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