Start from Vogüé at the beginning of the recently tarmac-surfaced cycle path, near the holiday village. To reach the car park, at the junction of the D114 and the D579, head towards the holiday village (opposite the signs for Lanas), and continue to the viaduct of the old railway line. Public parking spaces are available either just below the viaduct or at the viaduct itself.
(S/E) Take the footpath and cycle path towards Vogüé-Gare. It crosses the Ardèche, the D579a and then the D103.
(1) Continue along this path until you reach the D579.
(2) Cross the road carefully, first turning right then left. Follow the route – now tarmac-surfaced – of the old railway line until you rejoin the D579 just before Saint-Maurice-d’Ardèche.
(3) Turn right after crossing at the designated crossing, keeping to the left-hand side of the road facing the oncoming traffic, and you’ll soon find wider verges (cycle path, then pavement).
(4) Cross again at the pedestrian crossing towards Lanas, take the D114, and head for the bridge that spans both the Auzon and the Ardèche rivers, leading to the village of Lanas.
(5) Follow the main street, then take a street on the right to reach the church; cycle alongside it until you reach the banks of the Ardèche. Then follow a path that descends beneath the road’s retaining wall (recent, clearly marked yellow and white signposting).
A sign prohibits continuing along the riverbanks: follow the marked path and carry on straight ahead through a tunnel of vegetation until you reach a campsite, where the markings lead back towards the river.
Return to the banks of the Ardèche, follow them and reach the junction of the road from Lanas to Pradeloup.
(6) Turn right onto this road with caution to reach the junction with the D579.
(7) Cross very carefully and take Rue du Pigeonnier opposite, heading towards the holiday village, to return to the starting point (S/E).
You don’t seem to be fully aware of the effort involved. It doesn’t seem to me that you’ve properly read through all the feedback from previous users, some of whom had already made most of the points you’ve raised, which might have prevented you from undertaking this walk. I’m afraid you’ll find it hard to find any walks in the Ardèche – or perhaps elsewhere – that suit you, where there are no road crossings, which seems to me to be the absolute basics for any walker, with or without children.