Nevertheless , highway cargo movement increased rapidly in the 1960s and 1970s , doubling between 1970 and 1979 .
Most improvements have focused on local roads , and , in general , the country has been slow to develop modern highways .
Highway cargo movement increased rapidly in the 1960s and 1970s , doubling between 1970 and 1979 .
Most improvements have focused on local roads , and , in general , the country has been slow to develop modern highways .