In British English it is specifically defined as being where two roads cross each other (there are exactly 4 arms). Unlike the terms road intersection and road junction, crossroads is used in a more figurative or poetic sense (similar to fork in the road).
Originally the blues "Crossroads" was a literal right-angle crossing of two railroads - "where the Southern cross the Dog" - in Moorhead, Mississippi. The "Southern" was a line of the Southern Railway, sold to the Columbus and Greenville Railway in 1920, and the "Dog" was the "Yellow Dog", officially the Yazoo Delta Railroad, part of the Illinois Central Railroad system after 1897. This place is mentioned in a number of blues, including the recorded works of W. C. Handy and Bessie Smith.
This is particularly pronounced in conjure, rootwork, and hoodoo, a form of African American magical spirituality. In conjure practice, it is said that in order to acquire facility at various manual and body skills, such as playing a musical instrument, throwing dice, or dancing, one may attend upon a crossroads a certain number of times, either at midnight or just before dawn,and one will meet a "black man," whom some call the Devil, who will bestow upon one the desired skills. Evidence of this practice can be found in 20th century blues songs, such as Sold It to the Devil by Black Spider Dumpling (John D. Twitty). Although many modern listeners believe that the premier song about soul-selling at a crossroads is Crossroads Blues by Robert Johnson, the song may be a description of standing at a cross roads and trying to "flag a ride" or hitch-hike; the sense of foreboding coming from the singer's apprehension of finding himself, a young black man in the 1920s deep south, alone after dark and at the mercy of passing motorists. Others believe Robert Johnson sang this song in regards to the deal that was made with Legba in which Johnson exchanged his soul for his extraordinary guitar skills that seemed to appear suddenly. It should be noted, however that the idea of selling your soul for instrumental skills pre-dates the American South as several virtuoso classical musicians such as Paganini had stories told about selling their soul for music prowess (and that story may reference back to medieval troubadour doing something similar). The selling your soul for guitar power story has become a staple in both rock and metal guitarists.
Crossroads are very important both in Brazilian mythology (related to the headless mule, the devil, the Besta Fera and the Brazilian version of the werewolf) and religions (as the favourite place for the manifestation of "left-hand" entities such as Exus and where to place offerings to the Orishas).
There is also the now illegal tradition within England of burying criminals (particularly suicides) at crossroads. This may have been due to the crossroads marking the boundaries of the settlement coupled with a desire to bury those outside of the law outside the settlement, or that the many roads would confuse the dead. (See also Burial)
Symbolically, the crossroads can be used as a metaphor for the afterlife.