map-navigation project, highway information generally stored/represented?

navigation systems garmin tomtom have always preoccupied me. i've wanted exercise little map/navigation applications try out several pathing algorithms enhance trust them.

this twin biased question:

1.) map information stored? - have network roads, information generally stored? tools information defended inorder imitate map later? any highway stored array points where changes direction? kind record formats information stored in? there publically accessible libraries simply parsing files? does anyone have specifics map/road information stored/represented unequivocally helpful.

2.) navigation/pathing - doing simple pathing map information (a la garmin) audacity repremand converted trusty graph? any highway intersection zenith dilemma weights widen between vertexes? i pondering doing i try simple good famous pathing algorithms i get.

i've seen publically accessible map information us nonetheless i'm certain represented footnote adequate me means build trusty graph out it.

if anyone any information i conclude it. some-more footnote trust have better.