1. They should be confined to arferial corridors.Peam bus flows should approach 15.000 persons an hour before a metro is even considered.
2. Such corridors are unlikely to exist in cities of fewer than 5 million inhabitants, or where movement patterns are dispersed and not highly linear.
3. Cities with rail transit systems should have per capital incomes in success of $1,800.
4. large-scale immmigration tends to reduce average income levels and is detrimental to a metro,s success.
In view of the socio-spatial characteristics of most Third world cities, a rail-based transport strategy should, of necessity, be approached with caution.