A84 autoroute
Autoroute des Estuaires
Start of A84 at the Porte de Bretagne exit of the Périphérique Caen.
Route information
Part of E3 E46 E401
Length	170 km (110 mi)
Existed	2003–present
Major junctions
North end	Périphérique Caen
Major intersections	N 814 N 174 N 175 N 12 N 136
South end	Rocade Rennes
Location
Country	France
Major cities	Caen Rennes
Highway system
Roads in France Autoroutes Routes nationales

The A84 autoroute is a major motorway in western France completed on 27 January 2003 to connect the cities of Rennes in Brittany with Caen in Lower Normandy. It is part of the Autoroute des Estuaires from Belgium to Spain, avoiding Paris.

The motorway, 170 km long, cost a total of € 650 million. It is dual-carriageway both ways on its entire course and service areas are positioned at regular intervals. It is toll free.

The motorway was built with a special road surface to allow rain water to run off quickly, but it is ineffective with snow that often falls in large quantities in winter, so snowploughs are employed regularly. Motorway traffic radio 107.7 broadcasts A84 information specifically.

• 2 × 2 carriageway
• 170 km in length
• Total cost : €650 000 000 (2003)
• 3 speed camera zones
• 5 service areas (Aires de service et repos):
  • l'aire du mont Saint-Michel (Total), Saint-Aubin-de-Terregatte
  • l'aire de la Baie, Braffais
  • l'aire de la vallée de la Vire (Shell), Gouvets
  • l'aire de Cahagnes, Cahagnes
  • l'aire de Saint-Jean des Essartiers, Saint-Jean-des-Essartiers

The highway is free throughout its entire length. The various governments have studied the concession of this highway, but the regional authorities of Brittany and Normandy have convinced the public authorities to build and manage this highway with public funds.

• 1979: Ministerial decision to upgrade the road between Caen and Avranches to dual carriageway.
• 1987: Decision by the CIAT to connect Caen, Rennes and Nantes by motorway ensuring the continuity of the French motorway network.
• 1994: The connections between Caen and Avranches and Avranches and Rennes are declared of public utility.
• 27 January 2003: Opening of the last section of the A84 except the Rennes and Avranches bypasses.

A 84
Junction number & name	Northbound exits	Southbound exits
24	RN 136	RN 136
25	RD 812, Thorigné-Fouillard
26	RD 812 (RN 12), Liffré	RD 812 (RN 12), Liffré
27	RD 812 (RN 12), Liffré	RD 812 (RN 12), Liffré
28	RD 794, Saint-Aubin-du-Cormier	RD 794, Saint-Aubin-du-Cormier
La Chaîne / La Lande
29	RN 12, Fougères	RN 12, Fougères
30	RD 155, Saint-Brice-en-Coglès	RD 155, Saint-Brice-en-Coglès, Antrain
Le Coglais
31	RD 102, Coglès, Louvigné-du-Désert, Antrain	RD 102, Coglès, Louvigné-du-Désert
32	RD 30, Saint-James	RD 30, Saint-James
Le Mont Saint-Michel
33	RN 176, Pontaubault, Ducey	RN 176, Pontaubault, Ducey, Le Mont Saint-Michel
34	RN 175, Pontaubault, Le Mont Saint-Michel
35
36	RD 911, Avranches	RD 911, Avranches
La Baie du Mont Saint-Michel
37	RD 924, Villedieu-les-Poêles	RD 924, Villedieu-les-Poêles
38	RD 999, Villedieu-les-Poêles	RD 999, Villedieu-les-Poêles
La vallée de la Vire-Gouvets
39	RD 21, Tessy-sur-Vire	RD 21, Tessy-sur-Vire
40	RN 174	RN 174
41	RD 53, Saint-Martin-des-Besaces	RD 53, Saint-Martin-des-Besaces
Saint-Jean-des-Essartiers
42	RD 577, Coulvain	RD 577, Coulvain
43 Villers-Bocage	RD 30, Saint-James	RD 30, Saint-James
44 Villers-Bocage Nord	RN 175, Villers-Bocage
45	RD 92, Tournay-sur-Odon	RD 92, Tournay-sur-Odon
46	RD 174 (RN 175), Noyers-Bocage, Missy	RD 174 (RN 175), Noyers-Bocage, Missy
47		RD 147A, Version
48	RD 30, Saint-James	RD 30, Saint-James
49/9	RN 813, RN 175, Bretteville-sur-Odon, Caen	RN 813, RN 175, Bretteville-sur-Odon, Caen

The A84 is interrupted at Avranches. The bypass to the west of Avranches, by the RN 175 with two double lanes, has geometrical characteristics which do not allow the construction of motorway characteristics and status. An East motorway bypass for the A84 was therefore planned in the long term. The State bought 60 hectares of land and destroyed four houses along the route. However, the works are yet be launched. The land is still owned by the state.

The A84 is also to be extended to Nantes by upgrading the RN 137 dual-carriageway, thus creating a Caen-Rennes-Nantes route. This was abandoned, along with other projects of dual-carriageway upgrades in Brittany (RN 157 and RN 12 were planned to become A81 and RN 165 was planned to become A82).^[1]

In addition at Rennes, the construction of a "south-east bypass" will make it possible to avoid the Rennes ring-road on this route. Construction was due to commence from 2021 but was abandoned.

• A84 Motorway information in Saratlas