The improvement from Leeming By-pass to Catterick of some 4½ miles was completed in 1958 also by direct labour and involved constructing a second carriageway. The works were undertaken as and when funds became available and were carried out in sections.

Leeming is famous for its Royal Air Force base. The by-pass of Leeming was the second major scheme undertaken by the County's Workforce, with construction starting immediately after the completion of the Catterick By-pass.

Slightly higher width standards than at Catterick were authorised by the Ministry of Transport in that the overall effective width of 88 ft. incorporated dual 24 ft. wide carriageways, a 15 ft. wide central reservation, but only 3 ft. 6 in. wide hard shoulders in the verges.

The 3 mile long by-pass of Leeming Bar, Leeming and Londonderry, together with side road alterations was completed in 1961 at a cost of £1,002,000. The three overbridges and three underbridges were constructed using the same techniques as at Catterick, except that in the composite deck construction, stud welded shear connectors were used instead of angle-iron.

Carriageway construction comprised of 3 layers of gravel lean-mix concrete overlaid with 4 in. of 2-coat hot rolled asphalt. The gravel came from sources at Richmond and Catterick and the concrete was mixed in a 2 cu. yd. Automatic Weihmet paddle mixer. With workmen on shifts, the output from the machine regularly reached 1200 to 1300 tons per day.