When travel combined business and pleasures:
1. No transportation can be deducted if foreign travel in involved.
2. Transportation expenses must be allocated if domestic travel in involved.
3 . For Foreign trave, no allocations of transportion expenses is required if the taxpayer was away from home for seven days or less.
4. For Foreign trave, no allocations of transportion expenses is required if the taxpayer spends at least 25% of the time on business.