Felipe II made Madrid the capital of Spain because it was at the very center of his peninsular domains, and to this day many of the nation's highways radiate from Madrid like the spokes of a wheel. Originating at Kilometer 0—marked by a brass plaque on the sidewalk of the Puerta del Sol—these highways include the A6 (Segovia, Salamanca, Galicia); A1 (Burgos and the Basque Country); the A2 (Guadalajara, Barcelona, France); the A3 (Cuenca, Valencia, the Mediterranean coast); the A4 (Aranjuez, La Mancha, Granada, Seville); the A42 (Toledo); and the A5 (Talavera de la Reina, Portugal). The city is surrounded by the M30 (the inner ring road), and the M40 and M50 (the outer ring roads), from which most of these highways are easily picked up. To fight the heavy traffic leaving and getting into Madrid, the government set up an infrastructure plan that includes radial toll highways (marked R1, R2, R3, R4, and R5) that bypass the major highways by 50 to 60 km (31 to 37 mi), as well as the A41, a new toll highway connecting Madrid and Toledo. These options are worth considering, especially if you're driving on a summer weekend or a holiday.
That said, driving in Madrid is best avoided. Parking is nightmarish, traffic is heavy almost all the time, and the city's daredevil drivers can be frightening. August is an exception; the streets are then largely emptied by the mass exodus of madrileños on vacation.