I convert mp to shp by Global Mapper. Because the dbf files from Global Mapper are unusable in MPC, I wrote a program in FoxPro to change columns in the gbf files. For example one piece of this program:

alter table trasy add one_way n(1)
repla all one_way with 0
set filter to substr(routeparam,5,1)='1'
repla all one_way with 1

I also had to write another program in C to split lines of the mp file in their nodes.