Driving from France
The sole access route for the final approach to Andorra is the RN20, reached either via Ax-les-Thermes or via the Col de Puymorens.
NB: snowchains are obligatory on all approach roads.

After passing through the Franco-Andorran customs station, which straddles the RN20 road on the final approach to Andorra, continue straight on past the first roundabout to the border at Pas de la Casa town itself. There is a multi-storey car park at the huge silver-coloured sports complex to the right just after you cross the border; free open-air car parks are located in the town centre and at the top of Avinguda d'Encamp.

Grau Roig  For Grau Roig (and all other Andorran resorts), either take the Envalira Tunnel (toll) by turning to the right at the first roundabout on the approach to Pas de la Casa; or, drive straight through Pas de la Casa and continue climbing towards the Envalira Pass (Port d'Envalira).

At 2408 m (7900 ft), the Port d'Envalira is the highest road pass in the Pyrenees, and is often closed following heavy snowfall. On the far side of the pass, the access road to Grau Roig is clearly signed at the first junction.

Driving from Spain
The route from Spain is via the historic Catalan town of La Seu d'Urgell, just 10 km (6 miles) south of Andorra. As with the northern approach (from France), there is only one road leading into Andorra: here it is the N145.

NB: snowchains are obligatory on all approach roads.
After passing through customs and passport checkpoints at the border, the road becomes the CG1 and continues towards the Andorran town of Sant Julià de Lòria. On approaching Sant Julià, veer ahead-left at the first roundabout to bypass the town and head towards Andorra la Vella.

Rush-hour traffic through Andorra la Vella is no fun, but the government has made efforts to re-route traffic via a [still busy] bypass from the Santa Coloma district at the southern end of this small but bustling capital. Approaching the first suburbs, follow the signs to the right towards France (signed ‘França’) and Escaldes-Engordany. Take this bypass all the way straight up to the final exit, at the mini-roundabout past the upper end of Escaldes-Engordany: veer ahead-right here and continue up the main road (CG2), following the signs for Encamp and França.

The town of Encamp is 3 km (2 miles) from this point, and is easily bypassed by veering to the right at the first roundabout at the lower end of the town: follow the signs for Canillo and França and keep climbing on the main road, passing under the lines of Grandvalira's Funicamp cable car (there is a multi-storey car park at the base station here, just to the left).

Keep climbing straight on, passing through the villages of Canillo, El Tarter and Soldeu.  Beyond Soldeu, the Bordes d'Envalira is the final roadside hamlet before you reach the roundabout at the turn off [first exit ahead-left] for Grau Roig and the Envalira Pass (Port d'Envalira).
The quickest & easiest route to Pas de la Casa is via the Envalira Tunnel (toll), which is directly ahead at this roundabout. At the far side of the tunnel, turn right at the next roundabout for the final approach to the resort.

Pas de la Casa can also be reached via the Port d'Envalira, but, topping out at 2408 m (7900 ft), it's the highest road pass in the Pyrenees and can be closed following heavy snowfall.

Toulouse » Pas de la Casa
160 km (99 miles)

Barcelona » Pas de la Casa
174 km (108 miles)

Pas de la Casa » Grau Roig
5.5 km (3½ miles)
via Envalira Tunnel
or
10.5 km (6½ miles)
via Envalira Pass

Grau Roig » Andorra la Vella
25.5 km (16 miles)