Updates
Any person or group can submit improved solutions. After the solutions are checked, they will be included in CVRPLib. On the other hand, claims of new optimal solutions will only be accepted if a citable reference for the method used is provided. Each change in the status of an instance will be recorded chronologically on this page.
October 21, 2021
by CVRPLib
Improved solution reported by Francesco Cavaliere (University of Bologna), Emilio Bendotti, Matteo Fischetti (University of Padova, Italy), and Keld Helsgaun (Roskilde University, Denmark): Flanders2 (4375178).
June 30, 2021
by CVRPLib
Improved solutions reported by Martin Simensen (NTNU/SINTEF), Geir Hasle (SINTEF), and Magnus Stålhane (NTNU) using a hybrid approach that combines the Hybrid Genetic Search of Vidal, T. (2020) with Ruin & Recreate by Christiaens, J., & Vanden Berghe, G. (2020): X-n384-k52 (65928), X-n641-k35 (63682), Leuven2 (111397).
March 15, 2021
by CVRPLib
Proved optimal solutions using VRPSolver: X-n261-k13 (26558) and X-n856-k95 (88965).
January 30, 2021
by CVRPLib
Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): Antwerp2 (291371), Flanders2 (4375193), Ghent2 (257802), Leuven2 (111399).
January 27, 2021
by CVRPLib
Improved solutions reported by Luca Accorsi and Daniele Vigo (University of Bologna): Ghent2 (257910), Leuven2 (111415).
January 21, 2021
by CVRPLib
Improved solutions reported by Quoc Trung Dinh, Dinh Quy Ta, Duc Dong Do (ORLab, VNU University of Engineering and Technology, Vietnam), Thibaut Vidal (PUC-Rio), and Minh Hoàng Hà (ORLab, Phenikaa University, Vietnam): Brussels2 (345551), Flanders2 (4377305).
December 15, 2020
by CVRPLib
Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): X-n641-k35 (63684), X-n716-k35 (43373), X-n766-k71 (114417), X-n783-k48 (72386), Antwerp2 (291387), Brussels1 (501767), Brussels2 (345553), Flanders1 (7240845), Flanders2 (4377524), Ghent2 (257954), Leuven2 (111447).
November 14, 2020
by CVRPLib
Improved solutions by Vinícius R. Máximo and Mariá C.V. Nascimento (Universidade Federal de São Paulo) with a hybrid adaptive Iterated Local Search with diversification control: X-n384-k52 (65938), X-n641-k35 (63692), X-n716-k35 (43379).
November 6, 2020
by CVRPLib
Improved solutions by Eduardo Queiroga, Eduardo Uchoa, and Ruslan Sadykov through a POPMUSIC matheuristic: X-n401-k29 (66154), X-n491-k59 (66483), X-n536-k96 (94846), X-n733-k159 (136187), X-n749-k98 (77269), X-n766-k71 (114418), X-n783-k48 (72393), X-n936-k151 (132715), X-n979-k58 (118976), X-n1001-k43 (72355), Antwerp1 (477277), Brussels1 (501771), Flanders1 (7240874), Ghent1 (469532), Leuven1 (192848).
October 12, 2020
by CVRPLib
Improved solutions by Thibaut Vidal using a modern implementation of the Hybrid Genetic Search of Vidal et al. (2012), specialized to the CVRP, with one additional neighborhood: Golden_3 (10997.8), Golden_4 (13588.6), Golden_6 (8400.33), Li_25 (16665.7), Li_27 (17320).
October 10, 2020
by CVRPLib
Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): Antwerp2 (291400), Brussels1 (501854), Brussels2 (345565), Flanders1 (7241290), Flanders2 (4377626), Ghent1 (469586), Ghent2 (257958), Leuven2 (111489).
October 3, 2020
by CVRPLib
Improved solution by Eduardo Queiroga, Eduardo Uchoa, and Ruslan Sadykov through a POPMUSIC heuristic using exact VRPSolver, starting from a solution with value 1611.70 provided by Luca Accorsi and Daniele Vigo: Golden_16 (1611.28).
October 1, 2020
by CVRPLib
Improved solutions reported by Luca Accorsi and Daniele Vigo (University of Bologna): Golden_9 (579.70), Golden_10 (735.43), Golden_11 (911.98), Golden_15 (1337.27).
September 24, 2020
by CVRPLib
Improved solutions by Thibaut Vidal using a modern implementation of the Hybrid Genetic Search of Vidal et al. (2012), specialized to the CVRP, with one additional neighborhood: Antwerp1 (477306), Antwerp2 (291410), Brussels1 (501856), Brussels2 (345585), Flanders1 (7241335), Flanders2 (4377928), Ghent1 (469587), Ghent2 (257972), Leuven2 (111490).
September 21, 2020
by CVRPLib
Improved solutions by Thibaut Vidal using a modern implementation of the Hybrid Genetic Search of Vidal et al. (2012), specialized to the CVRP, with one additional neighborhood: X-n303-k21 (21736), X-n401-k29 (66163), X-n429-k61 (65449), X-n449-k29 (55233), X-n459-k26 (24139), X-n613-k62 (59535), X-n627-k43 (62164), X-n641-k35 (63694), X-n685-k75 (68205), X-n766-k71 (114454), X-n856-k95 (88965), X-n876-k59 (99299), X-n895-k37 (53860), X-n936-k151 (132725), X-n957-k87 (85465), X-n979-k58 (118987), X-n1001-k43 (72359).
September 7, 2020
by CVRPLib
Improved solutions by Eduardo Queiroga, Eduardo Uchoa, and Ruslan Sadykov through a POPMUSIC heuristic using exact VRPSolver: Brussels1 (501868), Flanders1 (7241397), Ghent1 (469599).
August 20, 2020
by CVRPLib
Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): X-n459-k26 (24140), X-n801-k40 (73305), X-n895-k37 (53870), Antwerp2 (291450), Brussels1 (501916), Brussels2 (345616), Flanders1 (7242182), Flanders2 (4377986), Ghent1 (469602), Ghent2 (258002).
August 12, 2020
by CVRPLib
Improved solutions by Eduardo Queiroga, Eduardo Uchoa, and Ruslan Sadykov through a POPMUSIC heuristic using exact VRPSolver: X-n313-k71 (94043), Antwerp1 (477323), Brussels1 (501934), Flanders1 (7242464), Ghent1 (469604), Leuven1 (192851).
August 8, 2020
by CVRPLib
Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): Antwerp1 (477535), Antwerp2 (291468), Brussels1 (502144), Brussels2 (345627), Flanders1 (7245214), Flanders2 (4378434), Ghent1 (469838), Ghent2 (258010), Leuven1 (192894), Leuven2 (111499).
July 31, 2020
by CVRPLib
Improved solutions reported by Luca Accorsi and Daniele Vigo (University of Bologna): X-n459-k26 (24141), X-n801-k40 (73311), X-n895-k37 (53906), X-n957-k87 (85467), Antwerp1 (477618), Antwerp2 (291526), Brussels1 (502273), Brussels2 (345743), Flanders1 (7248395), Flanders2 (4382022), Ghent1 (469891), Ghent2 (258116), Leuven1 (192915), Leuven2 (111544).