The following are the maximum speeds on certain highways in Brown County:

1. (1) U.S. Highway 12 in Aberdeen beginning 1.2 miles west of the west junction of U.S. Highway 12 and U.S. Highway 281, then east for 1.0 mile, fifty-five miles per hour; then east for 0.2 mile to the junction, forty-five miles per hour; then east for 3.09 miles, thirty miles per hour; then east for 1.1 miles, thirty-five miles per hour; then east for 0.8 mile, forty-five miles per hour; then east for 4.35 miles, fifty-five miles per hour; then east to a point 0.38 mile west of the junction with State Trunk Highway 37 in Groton, seventy miles per hour;
2. (2) U.S. Highway 12 beginning 0.38 mile west of the junction with State Trunk Highway 37 in Groton, then east for 0.17 mile, fifty miles per hour; then east for 0.51 mile, thirty-five miles per hour; then east for 0.22 mile, forty-five miles per hour; then east for 1.2 miles, sixty miles per hour; then east to the Day County line, seventy miles per hour;
3. (3) U.S. Highway 281 beginning at the junction of U.S. Highway 12 (6thAvenue) and U.S. Highway 281 (2ndStreet) in Aberdeen, then north 1.0 mile, thirty miles per hour; then north 1.92 miles, forty-five miles per hour; then north 2.3 miles, fifty-five miles per hour;
4. (4) State Trunk Highway 37 beginning 0.5 mile north of the junction with U.S. Highway 12 in Groton, then south for 0.15 mile, fifty miles per hour; then south for 1.22 miles, thirty-five miles per hour; then south for 0.21 mile, fifty miles per hour;
5. (5) State Trunk Highway 37 through Hecla beginning 0.1 mile south of Brown County Highway 5, then north 0.6 mile, forty-five miles per hour;
6. (6) On the service road which is parallel and adjacent to U.S. Highway 281, beginning 0.06 mile south of the centerline of U.S. Highway 12, then south on the service road 2.45 miles, forty-five miles per hour;
7. (7) State Trunk Highway 10 through Houghton, beginning 0.34 mile east of Brown County Highway 18, then west for 0.3 mile, fifty miles per hour; then west for 0.46 mile, thirty-five miles per hour; then west for 0.3 mile, fifty miles per hour;
8. (8) U.S. Highway 281 beginning at the south side of the junction of U.S. Highway 12 and U.S. Highway 281 in Aberdeen, then south for 0.3 miles, forty-five miles per hour; then south for 1.8 miles, fifty-five miles per hour; then south for 0.57 mile, sixty-five miles per hour; then south to the Spink County line, seventy miles per hour; and
9. (9) U.S. Highway 281 Truck Bypass beginning at the north side of the junction of U.S. Highway 12 and U.S. Highway 281, then north and east for 1.51 miles to the junction with U.S. Highway 281, forty-five miles per hour.

Source: SL 1975, ch 16, § 1; 7 SDR 25, effective September 22, 1980; 9 SDR 7, effective July 27, 1982; 9 SDR 35, effective September 19, 1982; 9 SDR 111, effective February 27, 1983; 13 SDR 129, 13 SDR 134, effective July 1, 1987; 14 SDR 85, effective December 23, 1987; 19 SDR 89, effective December 21, 1992; 19 SDR 128, effective March 8, 1993; 19 SDR 181, effective May 30, 1993; 20 SDR 96, effective December 29, 1993; 20 SDR 183, effective May 9, 1994; 21 SDR 61, effective October 2, 1994; 22 SDR 165, effective June 2, 1996; 24 SDR 165, effective May 31, 1998; 25 SDR 132, effective May 2, 1999; 26 SDR 124, effective April 2, 2000; 26 SDR 162, effective June 11, 2000; 28 SDR 24, effective August 29, 2001; 30 SDR 21, effective August 25, 2003; 30 SDR 171, effective May 11, 2004; 31 SDR 165, effective May 11, 2005; 32 SDR 53, effective October 10, 2005; 35 SDR 262, effective May 20, 2009; 44 SDR 95, effective December 5, 2017 ; 52 SDR 10, effective August 4, 2025 .

General Authority: SDCL 32-25-7 , 32-25-7.1 .

Law Implemented: SDCL 32-25-7 , 32-25-7.1 .

Prior versions effective: 2017-12-05, 2009-05-20.