In recent weeks the North Texas Tollway Authority board of directors has debated how to purchase legal services efficiently and how to select a new general counsel.

The nine-member NTTA board — which includes representatives from Collin, Dallas, Denton and Tarrant counties and supervises the construction and maintenance of toll roads in the region — plans to restructure its relationship with longtime outside counsel Frank Stevenson, a partner in Locke Lord Bissell & Liddell, and his Dallas-based firm, three board members and Stevenson say. The board also wants to spread its legal work among a broader group of firms in North Texas.