(1) The National Roads Authority may make bye-laws specifying in respect of any specified national managed road or specified part of a national managed road or specified carriageway or lane of a national managed road, the speed limit which shall be the speed limit on that road or those roads for mechanically propelled vehicles.

(2) The special speed limits that may be specified in bye-laws under this section are -

(a)

(i) 20 kilometres per hour,

(ii) 30 kilometres per hour,

(iii) 40 kilometres per hour,

in respect of a national managed road or nationally managed roads in accordance with guidelines issued by the Minister under this Part,

(b) 50 kilometres per hour, in respect of any national managed road other than a national managed road in a built-up area,

(c) 60 kilometres per hour,

(d) 80 kilometres per hour, in respect of a national managed road that is -

(i) a motorway,

(ii) a national road, or