Here is the road route from Pierry to CDG, Roissy:
151 km – about 1 hour 46 mins
1. Head west
1.9 km
2. Exit onto Rue de Madrid
0.3 km
3. Slight right at Place de Madrid
92 m
4. Place de Madrid turns slightly right and becomes Rue de Madrid
95 m
5. At the traffic circle, take the 1st exit onto Rue de New York
1.2 km
6. At the traffic circle, take the 2nd exit onto Rue de la Fossette
0.6 km
7. At the traffic circle, take the 1st exit onto D212/Route Périphérique Aéroport de Paris-Roissy-Charles de Gaulle
Continue to follow D212
Go through 1 traffic circle
3.3 km
8. Merge onto N2 via the ramp to A4/A1/Marne-la-Vallée/Villepinte
4.9 km
9. Take the exit onto A104 toward Marne-la-Vallée/Mitry-Mory/Villeparisis
19.5 km
10. Take the exit onto A4 toward Metz/Nancy/Reims
Partial toll road
89.4 km
11. Take exit 21-Dormans toward Epernay/Fismes
Partial toll road
1.3 km
12. Keep left at the fork, follow signs for Ville-en-Tardenois
36 m
13. Turn left at D980
0.4 km
14. Take the 1st right onto D23e
2.8 km
15. Continue straight onto D23
6.1 km
16. At the traffic circle, take the 3rd exit onto D1
3.0 km
17. Turn right at D601
0.7 km
18. Take the 1st left onto N3
12.0 km
19. At the traffic circle, take the 1st exit onto Avenue Jean Jaurès/D951 heading to A4/A26/Châlons-en-Champagne/Sézanne
Continue to follow D951
0.6 km
20. Turn right at Boulevard du Cubry/D951
Continue to follow D951
Go through 1 traffic circle
1.9 km
21. At the traffic circle, take the 1st exit onto Rue Jules Lobet
0.4 km
22. Continue onto Rue du Général de Gaulle
0.3 km
Not too complex and doable in less than 2 hours, so that means if they have U-drive vehicles they might do that. Or they could take a taxi that distance, quite expensive but very fast.