The 2006 population estimate of Madison was 223,389, making it the second largest city in Wisconsin, after Milwaukee, and the 82nd largest in the United States. The city forms the core of the United States Census Bureau's Madison Metropolitan Statistical Area, which includes all of Dane County and neighboring Iowa and Columbia counties. The Madison MSA had a 2006 estimated population of 543,022, and is one of the fastest-growing in Wisconsin.
As of the census of 2000, there were 208,054 people, 89,019 households, and 42,462 families residing in the city. The population density was 3,029.7 people per square mile (1,169.8/km²). There were 92,394 housing units at an average density of 1,345.4/sq mi (519.5/km²). The racial makeup of the city was 83.96% White, 5.84% African American, 0.36% Native American, 5.80% Asian, 0.04% Pacific Islander, 1.67% from other races, and 2.32% from two or more races. 4.09% of the population were Hispanic or Latino of any race.
There were 89,019 households out of which 22.1% had children under the age of 18 living with them, 37.0% were married couples living together, 7.8% had a female householder with no husband present, and 52.3% were non-families. 35.3% of all households were made up of individuals and 7.1% had someone living alone who was 65 years of age or older. The average household size was 2.19 and the average family size was 2.87.
In the city the population was spread out with 17.9% under the age of 18, 21.4% from 18 to 24, 32.2% from 25 to 44, 19.3% from 45 to 64, and 9.2% who were 65 years of age or older. The median age was 31 years. For every 100 females there were 96.6 males. For every 100 females age 18 and over, there were 95.0 males.
The median income for a household in the city was $41,941, and the median income for a family was $59,840. Males had a median income of $36,718 versus $30,551 for females. The per capita income for the city was $23,498. About 5.8% of families and 15.0% of the population were below the poverty line, including 11.4% of those under age 18 and 4.5% of those age 65 or over.
Madison is the larger principal city of the Madison-Baraboo CSA, a Combined Statistical Area that includes the Madison metropolitan area (Columbia, Dane, and Iowa counties) and the Baraboo micropolitan area (Sauk County), which had a combined population of 556,999 at the 2000 census.
Madison is served by the Dane County Regional Airport, which serves more than 100 commercial flights on an average day, and nearly 1.6 million passengers annually. Madison Metro operates bus routes throughout the city and to some surrounding towns. Madison has three taxicab companies, as well as several companies that provide specialized transit for individuals with disabilities.
A commuter light rail system has been proposed, particularly for a corridor passing through the isthmus and alongside the university campus, but has remained on paper for decades. A high-speed rail route from Chicago through Milwaukee and Madison to Minneapolis/St. Paul, Minnesota, has also been proposed as part of the Midwest Regional Rail Initiative. The nearest train station is in Columbus, Wisconsin. Regional buses connect Madison to Milwaukee, Janesville, Beloit, LaCrosse, and in Illinois, Rockford, O'Hare Airport, and Chicago. Service is also available to St. Paul, Minnesota.
Railroad freight services are provided in Madison by Wisconsin and Southern Railroad (WSOR) and Canadian Pacific Railway (CP). Wisconsin & Southern has been operating since 1980, having taken over trackage owned since the 19th century by the Chicago and North Western and the Milwaukee Road. Some of the proposed light rail and commuter routes would use existing WSOR rights-of-way, such as the line between the Kohl Center and Middleton. Limited commuter trains were tested along this line in the early 2000s as "football specials". The trains took passengers from the Middleton depot to Camp Randall Stadium to help alleviate parking issues on game days.
A number of bus lines connect Madison to nearby cities. Badger Bus, connects Madison to Milwaukee running multiple buses a day. Greyhound Lines, a nationwide bus company, has a local stop and offers routes through most of the country. Van Galder Bus Company, a subsidiary of Coach USA, provides transportation through Rockford to Chicago - Downtown at the Amtrak station, O'Hare Airport and Midway Airport. Mad-Bus provides transportation for University of Wisconsin students to the Twin Cities. First Student offers charter bus rental services to groups in the Madison and Milwaukee area.
I-39, I-90, and I-94 expressways intersect at Madison, connecting the city to Milwaukee; Chicago; Rockford, Illinois; Minneapolis-St. Paul and Wausau. U.S. Routes US-12, US-14, US-18, US-51 and US-151 connect the city with Dubuque, Iowa, the Wisconsin cities of Lacrosse and Janesville, and Lake Michigan. The Beltline is a six-to-eight lane freeway on the south and west sides of Madison and is the main link from downtown to the southeast and western suburbs.