Colmar to Spa Road Trip: Ultimate Guide to Route A35-E42

When driving from Colmar to Spa, you traverse 310 kilometers of the most varied landscapes in Europe. The quickest route uses the A35 then A4/E25 north toward Luxembourg and then the E42 to Belgium, taking about 3 hours and 15 minutes without stops. Notably, just after leaving Colmar, you pass under the Vosges foothills near the A35 exit 23, where the highway briefly narrows to two lanes—a quirk that often surprises drivers.

Road quality is generally excellent throughout: the A35 and A4 are smooth asphalt with good night lighting up to 10 km before Luxembourg. In the Ardennes section of E42, watch for sharp curves and occasional deer crossing signs. No major toll gates except the Luxembourg border. Speed cameras are frequent on the A4 near Nancy and Metz.

• Safety tip: On the descent from the Vosges (A35 south of Saverne), use engine braking to avoid brake fade; the gradient reaches 8% for 3 km.
• Night illumination: Complete on A35/A4, but on E42 in Belgium, sections near the German border have intermittent lighting.

Family-friendly stops include the Parc de la Muette (exit 12 from A35) with a large playground and mini-golf. Interactive museums: Le Musée de la Resistance (exit 30.1 on A4) offers hands-on exhibits for ages 8+. For pet relief, the Aire de la Marne (A4 km 45) has a designated dog park with waste bags.

• Pet-friendly cafes: Café de la Gare in Arlon (5 min off E42) allows dogs on the terrace and provides water bowls.

Fatigue management: The long straight section on the A4 between Nancy and Metz can induce drowsiness. Recommended rest zones for naps: Aire de la Meurthe (A4 km 25) has shaded parking lots and quiet rest cabins. In the Ardennes, the Rastaman Park (Belgium exit 10) has a safe parking area with CCTV.

• Hidden off-route spots: 5 minutes from the A35 near Schirmeck, the abandoned Fort de Mutzig (a pre-WWII fortification) is open for self-guided tours.
• Another gem: Château de Crusnes (exit 32.1 A4) – a 13th-century castle ruin on a hillock with free parking.

Fuel efficiency matters on this route due to elevation changes. The A35 climbs nearly 400 meters from Colmar (alt. 200 m) to the Vosges pass near Saverne (alt. 600 m). Expect fuel consumption to increase by 10-15% on this segment. Diesel prices in France average €1.70/L, while Luxembourg offers cheaper fuel (€1.50/L). Plan to fill up at the Total station near the Luxembourg border (exit 3 on A3).

• Total driving distance: 310 km
• Estimated fuel cost (diesel car, 7 L/100km): ~€37 in France, ~€33 if filling in Luxembourg
• Tool booths: A35 and A4 are toll-free, but the A3 in Luxembourg has a toll (€3.20 for cars)

Rest areas are well-distributed: Aire de la Zorn (A4 km 30) has clean toilets, picnic tables, and a playground. For a longer break, consider the service area near Thionville (A31, exit 32) with restaurants and a fuel station. The how to find the best stops and hidden gems between cities article offers additional strategies for planning stops.

The geographical shift is dramatic: Colmar sits in the Alsatian plain with vineyards and the Vosges Mountains. Crossing through the Vosges at the Saverne Pass, you enter the Lorraine plateau, then descend into the Moselle valley near Luxembourg. By the time you reach Spa, you're in the Ardennes Massif, characterized by rolling hills and forests.

• Colmar to Saverne: Vineyards and spruce forests; stop at the Mont Sainte-Odile viewpoint (5 min detour) for a panoramic shot of the Rhine rift.
• Saverne to Luxembourg: Open farmland, then industrial valleys near Thionville; look for the remnant Maginot Line fortifications visible from the A4.
• Luxembourg to Spa: The valley of the Ourthe river; the E42 winds through wooded hills with occasional limestone cliffs.

UNESCO World Heritage sites: While none lie directly on the route, a 20-minute detour from the A4 east of Metz brings you to the Pont du Diable (not actually a bridge but a geological oddity). The official UNESCO site of the Strasbourg Cathedral is a 30-minute drive south of the route near the start. For culture, stop at Dalheim (Luxembourg) to buy traditional knipp (meat loaf) at the weekly farmers market (Wednesday morning).

• Regional roadside produce: In Alsace, look for tarte flambée kits at the Aire de la Vaine (A35); in Luxembourg, try gromperekichelcher (potato fritters) at stalls near the A3 rest area.
• Craft shops: The village of Bouillon (detour 20 min from the E42 on N89) has a glassblowing studio open to visitors.