Hi Chuck -- I could have sworn this question was posted before...but anyways...the two ways you can go:
Via Autopista 1. From Guadarrama take the A-6 towards A Coruņa.
2. As soon as you pass through the Guadarrama tunnel, get into your right hand lane. This will automatically exit onto the A-61. This is the new highway just opened that connects Madrid (via the A-6) to Segovia. From this point, you are 15 minutes from Segovia. Be sure to stay in the lane and follow the sign for Segovia. There will be a toll that you have to pay.
3. As you approach Segovia, you will pass through some traffic circles. At the second traffic circle, make a left turn (going 3/4 around the circle) and on your right hand side will be a tourist office.
Via Scenic Route 1. From Guadarrama, follow the N-VI (main road passing north through Guadarrama)...itīs a curvy road and will take you through the mountain pass of the Guadarrama mountains. For the best mountain spring water, stop at the fountain on the other side of the mountains. There are usually several cars pulled over on both sides of the road filling up their water bottles.
2. Once you have come down the other side of the mountains you will enter into the town of San Rafael (about 20 minutes).
3. Continue to the center of San Rafael where you will see signs for the A-6 and for the local highway SG-503 (SG=Segovia). At the intersection (there is a Galp gas station on the right), bear right, pass through the traffic circle and continue straight on the SG-503.
4. This highway (sometimes one, two or four lanes) will take you through lovely countryside and farmland to Segovia. (From San Rafael it will take about 30 minutes).
5. As you approach Segovia, you will pass through some traffic circles. At the second traffic circle, make a left turn (going 3/4 around the circle) and on your right hand side will be a tourist office.
Check out
CAMPSA for a route calculator.
Happy travels!
Have fun!