The Minister of Transport and the Secretary of State acting jointly may make regulations prescribing the conditions under which the rights conferred by this section may be exercised, and such regulations may in particular make provision as to—
the construction of any appliances or vehicles used under this section,
the maximum weight of any such appliances or vehicles, or the maximum weight borne by any wheel or axle,
the maximum speed of any such appliances or vehicles,
the hours during which the appliances or vehicles may be used, and
the giving by the Minister of Transport or the Secretary of State of directions dispensing with or relaxing any requirement of the regulations as it applies to a particular authority or in any particular case.