Autoroute 55 (also called Autoroute de l'Énergie north of the Autoroute 20 and Autoroute Joseph-Armand Bombardier south of it) is an important north–south Autoroute and the only one running in that direction in central Quebec. It is the longest north-south Autoroute, beginning as the continuation of I-91 at the Canada–United States border near Stanstead and continuing to Shawinigan, where it downgrades to Route 155. The total length of A-55 is currently 247 km (153.5 mi) long, including concurrencies with Autoroute 10, Autoroute 20 and Autoroute 40.

Autoroute 55 connects the mid-sized communities of Magog, Sherbrooke, Drummondville, Trois-Rivières, and Shawinigan and the smaller communities in between. The most notable feature on A-55 is the Laviolette Bridge between Trois-Rivières and Bécancour, which is one of the longest bridges in Quebec and in Canada.

A-55 had a short "gap" between Bécancour and Drummondville until October 2006. The gap resulted from Transports Quebec's original intention of bringing A-55 southeast towards Victoriaville along what is now Autoroute 955 before shifting southwest to rejoin existing A-55 near Richmond. However, plans changed in the 1970s, and the present routing was chosen. The southern section was originally supposed to be Autoroute 51 and was intended to continue to the planned extension of Autoroute 30 in Pierreville. A-55 was signed along Route 155 (which is not an Autoroute-standard highway) until the new route was completed.

All of the southern portion of A-55 became a full four-lane freeway by the end of October 2006. The gap being filled in the northern portion will initially be a two-lane freeway for about 20 km (12.4 mi), but it is intended to ultimately be four lanes.

The designation Autoroute Joseph-Armand Bombardier is in honour of Quebec businessman Joseph-Armand Bombardier, who lived in Valcourt, near where A-55 passes and who invented the snowmobile there. His company, Bombardier Inc., started by building snowmobiles and eventually grew into a major international manufacturer of transit vehicles and aircraft.

The designation Autoroute de l'Énergie means "Energy Highway" since it provides access to the Gentilly Nuclear Generating Station in Bécancour and the hydroelectric facilities in Shawinigan and the Haut-Saint-Maurice area, but the section north of A-30 is likely to remain at its comparatively short length to Shawinigan for the foreseeable future.

RCM	Location	km	mi	Old exit	New exit	Destinations	Notes
Memphrémagog	Stanstead	0.00	0.00		—	I-91 south – Derby Line, Newport	Continuation into Vermont; A-55 / Autoroute Joseph-Armand Bombardier southern terminus
				Canada–United States border at Derby Line–Rock Island Border Crossing
		0.3	0.19			R-247 west (Boulevard Notre-Dame)	At-grade intersection, traffic signals
		2.0	1.2		2	R-143 (Rue Dufferin) – Stanstead
	Stanstead-Est	5.7	3.5	Curtis Rest Stop (Northbound)
	Sainte-Catherine-de-Hatley	20.7	12.9		21	R-141 – Ayer's Cliff, Coaticook
		28.7	17.8		29	R-108 – Sainte-Catherine-de-Hatley, North Hatley, Sherbrooke
	Magog	31.8	19.8		32	Rue-Saint-Patrice, Boulevard Industriel
		33.1	20.6		33	R-112 – Magog (Centre-Ville)
		34.4	21.4	34 71	34 121	A-10 west – Montréal	South end of A-10 concurrency; northbound signed as exits 34-E (east) and 34-O (west); southbound signed as exit 121; exit numbers follow A-10
Memphrémagog–Sherbrooke boundary	Magog–Sherbrooke boundary	36.7– 37.8	22.8– 23.5	72 36	123	R-112 (Rue Sherbrook) to R-249 – Magog (Centre-Ville), Saint-Denis-de-Brompton	R-112 follows A-10 / A-55 service roads
Sherbrooke		41.0	25.5	41	128	R-112 (Boulevard Bourque)	R-112 exits A-10 / A-55 service roads
		46.9	29.1	46	133	Chemin Saint-Roch Nord
		49.6	30.8	Catherine-Day Truck Stop (Northbound)
		50.9	31.6	50	137	R-220 (Boulevard Industriel), Chemin de Saint-Élie
		54.4	33.8	54	140	A-410 east to R-108 (Rue King) – Cookshire-Eaton
		55.2	34.3	55	141	Boulevard de Monseigneur-Fortier
		56.9	35.4		143	A-10 ends / A-610 east (Autoroute Louis-Bilodeau) to R-112 – Sherbrooke Centre-Ville, East Angus, Lac-Mégantic	A-10 eastern terminus; north end of A-10 concurrency
		58.0	36.0		58	R-222 (Chemin des Écossais) – Saint-Denis-de-Brompton, Valcourt	A-55 exit numbers resume
		60.1	37.3		60	Rue Laval
Le Val-Saint-François	Windsor	71.0	44.1		71	R-249 – Windsor, Saint-François-Xavier-de-Brompton	Signed as exits 71N (north) and 71S (south) northbound
	Melbourne	84.5	52.5		85	R-243 – Racine, Valcourt, Melbourne	Melbourne Service Centre
		88.7	55.1		88	R-116 – Acton Vale, Richmond, Val-des-Sources
	Ulverton	97.7	60.7		98	Chemin Mooney	Northbound exit and entrance
Drummond	L'Avenir	104.1	64.7		103	Lefebvre, L'Avenir, Ulverton, Durham-Sud
	Drummondville	111.3	69.2		111	Route Caya
		116.4	72.3		116	R-139 – Wickham, Acton Vale, Granby, Drummondville
		122.0	75.8		122	Boulevard Jean-de-Brébeuf – Drummondville
		125.4	77.9		125	R-122 – Saint-Germain-de-Grantham, Drummondville
		128.0	79.5		128 173	A-20 (TCH) west – Montréal	South end of A-20 concurrency; exit numbers follow A-20; north end of Autoroute Joseph-Armand Bombardier
		125.4	77.9		175	R-143 north (Boulevard Lemire) – Saint-Bonaventure, Saint-François-du-Lac	South end of R-143 concurrency
		131.3	81.6		177	R-143 south – Saint-Majorique-de-Grantham, Drummondville	North end of R-143 concurrency
		133.6	83.0		179	Chemin du Golf
		135.1	83.9		181	Drummondville
	Saint-Cyrille-de-Wendover	139.9	86.9		185	R-255 – Baie-du-Febvre, Saint-Cyrille-de-Wendover, Saint-Félix-de-Kingsey
	Notre-Dame-du-Bon-Conseil	145.9	90.7		191	Sainte-Brigitte-des-Saults
		150.8	93.7		196	R-259 – Nicolet, Sainte-Perpétue, Notre-Dame-du-Bon-Conseil
Drummond – Nicolet-Yamaska boundary	Notre-Dame-du-Bon-Conseil – Saint-Léonard-d'Aston boundary	154.1	95.8		200	Saint-Léonard-d'Aston	Former R-155 north
Nicolet-Yamaska	Saint-Léonard-d'Aston	156.1	97.0		202	Rang du Moulin-Rouge
	Sainte-Eulalie	157.3	97.7		204	Rang des Cédres, Rang des Plaines
		163.4	101.5		210 145	A-955 south – Saint-Samuel, Saint-Albert, Victoriaville, Warwick A-20 (TCH) east to R-161 – Québec, Sainte-Eulalie, Saint-Valère	North end of A-20 concurrency; A-955 exit 15; A-55 exit numbers resume; south end of Autoroute de l'Énergie
	Saint-Wenceslas	171.8	106.8		153	Saint-Léonard-d'Aston, Saint-Wenceslas
	Saint-Célestin	183.2	113.8		—	R-226 – Saint-Célestin	At-grade intersection, traffic signals; interchange proposed; former R-155 south / R-161 south
Bécancour	Bécancour	186.3	115.8		—	Rang Prince	At-grade intersection; to be removed as part of the A-55 widening project
		188.1	116.9		—	Chemin Forest – Précieux-Sang	At-grade intersection; to be removed as part of the A-55 widening project
		189.8	117.9		—	Chemin Thibodeau	At-grade intersection; to be removed as part of the A-55 widening project
		191.9	119.2		173	Bécancour, Nicolet, Wôlinak
		194.3– 195.4	120.7– 121.4		176	A-30 / R-132 – Bécancour, Sainte-Angèle	A-30 exit 209
St. Lawrence River		196.2– 198.8	121.9– 123.5	Pont Laviolette (Laviolette Bridge)
Trois-Rivières		198.8	123.5		181	R-138 (Rue Notre-Dame, Boulevard Gene-H.-Kruger)
		200.6	124.6		182	A-40 east – Trois-Rivières (Centre-Ville), Québec	South end of A-40 concurrency; A-40 exit 197
		201.2	125.0		183	Boulevard Jean-XXIII
		204.1– 204.6	126.8– 127.1		186	A-40 west / Boulevard des Forges – Montreal	North end of A-40 concurrency; A-40 exit 196
		209.3	130.1		191	Boulevard Industriel, Boulevard Saint-Michel
		214.6	133.3		196	Boulevard des Forges – Yamachiche
Maskinongé	Saint-Étienne-des-Grès	219.9	136.6		202	Saint-Étienne-des-Grès, Saint-Barnabé
		222.9	138.5	Grès Rest Stop (Northbound, seasonal)
		224.4	139.4		206	Saint-Boniface
	Saint-Boniface	229.8	142.8		211	R-153 – Saint-Boniface, Shawinigan
Shawinigan		234.4	145.6		216	Rue Burrill
		235.8	146.5		217	R-351 (Rue Garnier) – Saint-Mathieu-du-Parc
		238.1	147.9		220	Boulevard Hubert-Biermans, Boulevard Vallée-du-Parc
		241.4	150.0		223	Avenue de Grande-Mère, 25 rue
		244.5	151.9		226	Chemin du Parc National, 8 rue
		246.5	153.2	Pont des Piles (Piles Bridge) crosses Saint-Maurice River
					—	R-155 north – Grandes-Piles, La Tuque	A-55 / Autoroute de l'Énergie northern terminus; continues as R-155
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus       Incomplete access       Route transition       Unopened

There are three rest areas found on A-55 and none are full service centre as most are near populated areas that can provide services for travellers.

Location	Name	km	Direction	Services
St-Etienne-Des-Gres	Autoroute de l'Énergie Rest Area		Northbound	Parking for trucks and cars (maximum 4 hours stop time), tourist information booth and rest rooms. Located across from Saint-Boniface-de-Shawinigan Weight Station
Ulverton	Halte du Moulin		Southbound	Parking area only (maximum 4 hours stop time) located near Moulin A Laine D'Ulverton. No services available - rest room and tourist information building demolished before 2015. Near stop for food and restrooms is McDonald's two exits down in Melbourne.
Stanstead, Quebec	Halte Curtis		Northbound	Parking for cars, RVs and trucks only (maximum 4 hours stop time). Rest rooms are closed and portable toilets removed from site. Motorists have more options available (food, rest rooms and fuel) by travelleing either north (about 27 km) to Magog or back south (about 4 km) in Stanstead.

On April 2, 2024, Drummondville news outlet Vingt55 reported that Transport Minister Geneviève Guilbault alongside Minister Responsible for the Centre-du-Québec Region André Lamontagne announced in Drummondville that the Government of Quebec has made a two-year investment of CAD$274,442,000 in the roadways of the Centre-du-Québec region, and that part of the money would be going towards converting A-55 between Sainte-Eulalie and Bécancour from a super two to a standard four-lane freeway. Announcements regarding rest areas being renovated or revamped along the highway are expected to come at a later date.

• 
  Autoroute 55 southbound
• 
  Southbound view, showing super two undivided highway
• 
  Multiplex of Autoroutes 20 and 55
• 
  Southbound from Trois-Rivières at exit 181, approaching the Laviolette Bridge

• A-55 at motorways-exits.com
• A-55 at Quebec Autoroutes
• Transports Quebec Map