The site's racing history predates the current oval. In 1961, Keith Bryar opened 106 Midway Raceway, a quarter-mile dirt oval that hosted go-karts, midgets, and stock cars. By 1965, Bryar had expanded the complex into Bryar Motorsports Park, adding a 1.6-mile, ten-turn road course built to host the Loudon Classic motorcycle race. The facility struggled financially through much of the 1970s and faced recurring safety incidents.
In December 1988, Maine businessman Bob Bahre bought the facility from Bryar for $950,000 with the stated ambition of attracting NASCAR Cup Series and CART races. After clearing environmental and legal objections, a groundbreaking ceremony was held in August 1989 and the newly named New Hampshire International Speedway (NHIS) opened its oval for racing in July 1990 with a Busch Series event won by Tommy Ellis. The construction cost reportedly reached $25 million by the time the project was complete.
Bahre's first major benchmark arrived in 1992 when CART held an Indy car race at the facility, won by Bobby Rahal. The venue obtained its first Cup Series race in 1993, with Rusty Wallace winning the inaugural event. Through the 1990s, Bahre expanded seating aggressively: capacity grew from the original configuration toward a peak of 91,000 by the early 2000s, making it one of the largest venues in New England.
In its current form, NHMS measures 1.058 miles with progressive banking of 2 to 7 degrees in the turns and just 1 degree of banking on the straights. The shallow banking and flat corners give the track its distinctive character — tight, abrasive, and demanding on both tires and handling balance. NASCAR uses the 1.058-mile measurement while the IndyCar Series used a slightly shorter measurement of 1.025 miles. Alongside the main oval, the venue retains the original 1.6-mile, 12-turn road course used primarily for the annual Loudon Classic motorcycle event.
The early 2000s brought serious safety concerns to NHIS. In May 2000, Busch Series driver Adam Petty was killed during a practice session when his car suffered a stuck throttle and crashed into the third-turn wall. Two months later, Cup Series driver Kenny Irwin Jr. died in almost identical circumstances at the same corner. The twin tragedies prompted significant scrutiny of the track's turn geometry, which featured a sharp radius and limited banking. NASCAR and track officials responded with a major reconfiguration: the track was repaved in 2002, the turns were made twelve feet wider, and banking was reduced from twelve degrees to six to seven degrees in an effort to create a second racing groove and improve safety. SAFER barriers were installed in 2003.
In November 2007, Speedway Motorsports, Inc. and its owner Bruton Smith purchased the facility from Bahre for $340 million. The sale was finalized in January 2008 and the track was renamed New Hampshire Motor Speedway. Under SMI's stewardship, attendance gradually declined: the peak capacity of 91,000 was reduced to 74,000 in 2018, then to 44,000 in 2021 as NASCAR's broader attendance challenges continued across the sport.
NHMS hosts one NASCAR weekend per year. The flagship event is the Mobil 1 301, a Cup Series race. A NASCAR Truck Series race called the EJP 175 runs as a support event. The venue formerly hosted an Xfinity Series race as well. IndyCar returned for a one-off appearance in 2011 after a gap since 1998 but did not renew due to low attendance.
The Loudon Classic motorcycle race has been held at the facility continuously since 1965 and remains the venue's longest-running annual event.
New Hampshire Motor Speedway appears in several sim racing titles as a representative example of the short, flat D-shaped ovals that make up a distinctive tier of the NASCAR calendar. Its demanding combination of narrow racing grooves, abrasive surface, and minimal banking rewards precise setup work and chassis balance rather than raw speed, making it a meaningful challenge in simulation contexts.