The President George Bush Turnpike (PGBT) is a 52-mile (84 km) controlled-access toll road running through the northern, northeastern and western suburbs, forming a partial beltway around Dallas, Texas, United States. It is named for the late George H. W. Bush, the 41st president of the United States. At its west end near Belt Line Road in Irving, State Highway 161 continues southwest to I-20 in Grand Prairie. The discontinuous free frontage roads along the turnpike from I-35E in Carrollton east to its end at I-30 in Garland are assigned the State Highway 190 designation. SH 190 signage appears only along the Rowlett, Garland, Richardson, Plano, and Carrollton sections of the frontage road with the undersign "frontage road only". At intersections with city streets, only the Bush Turnpike signs are displayed, not the SH 190 signage. Prior to the construction of the main lanes as a tollway, SH 190 was used as the name of the planned main lanes too. Similarly, the part west of I-35E was planned as part of SH 161. Bush Turnpike is signed as a north–south road from I-20 to I-35E, an east–west road from I-35E to the Merritt Main Lane Gantry and as a north–south road from the Merritt Main Lane Gantry to I-30, as Bush Turnpike makes a nearly 90-degree curve in both places.