 Casino gambling was introduced in both towns in the early 1990s, but had more success in Black Hawk (which has 18 casinos) than in Central City (which has 6 casinos), partly because the main road to Central City passed through Black Hawk, tempting gamblers to stop in Black Hawk instead.In an effort to compete, Central City completed a four-lane, parkway from Interstate 70 to Central City, without going through Black Hawk.The highway was completed in 2004, but Black Hawk, which prior to the introduction of gambling was much smaller than Central City, continues to generate more than seven times the gambling revenue that Central City does.