William Kissam Vanderbilt II, the great-grandson of Cornelius Vanderbilt, was an auto-racing enthusiast and created the Vanderbilt Cup, the first major road racing competition, in 1904. He ran the races on local roads in Nassau County during the first decade of the 20th century, but the deaths of two spectators and injury to many others showed the need to eliminate racing on residential streets. Vanderbilt responded by establishing a company to build a graded, banked and grade-separated highway suitable for racing that was also free of the horse manure dust often churned up by motor cars. The resulting Long Island Motor Parkway, with its banked turns, guard rails, reinforced concrete roadbed, and controlled access, was the first limited-access roadway in the world.
The road was originally planned to stretch for 70 miles (110 km) in and out of New York City as far as Riverhead, the county seat of Suffolk County, and point of division for the north and south forks of Long Island. Only 45 miles (72 km) (from Queens in New York City to Lake Ronkonkoma) were constructed, at a cost of $6 million. Construction began in June 1908 (a year after the Bronx River Parkway). On October 10, 1908, a 10-mile-long (16 km) section opened as far as modern Bethpage. It hosted races in 1908 and on the full road in 1909 and 1910, but an accident in the latter year's Vanderbilt Cup, killing two riding mechanics with additional injuries, caused the New York Legislature to ban racing except on race tracks, ending its career as a racing road.
By 1911, the road was extended to Lake Ronkonkoma. Its western stretch was also extended from Great Neck to what is now Fresh Meadows. The Long Island Motor Parkway was the first roadway designed exclusively for automobile use, the first concrete highway in the United States, and the first to use overpasses and bridges to eliminate intersections.
According to wikipedia