Updates

Solution Updates

Any person or group can submit improving solutions to one of the authors of Uchoa et al. (2017). 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 (like a technical report) for the used method is provided. Each update in the status of an instance will be recorded chronologically in this tab.

  • October, 15 2024 - Proven optimal VRPTW solution by Anthony Karahalios (Carnegie Mellon University) and Willem-Jan van Hoeve (Carnegie Mellon University) using a column elimination approach: C2_10_1 (16841.1).
  • July, 29 2024 - Improved solutions reported by Marcelo Maia (Universidade Federal Fluminense) using MDM-HGS and HGS-CVRP: Loggi-n601-k42 (347046), ORTEC-n701-k64 (445541).
  • July, 25 2024 - Proven optimal VRPTW solutions by João Marcos Pereira Silva, Eduardo Uchoa, and Anand Subramanian using the Cluster Branching strategy: RC1_4_1 (8522.9), RC1_4_2 (7878.2), R1_4_2 (8873.2), R1_4_5 (9184.6), R1_4_6 (8340.4), C1_6_10 (13617.5).
  • December, 14 2023 -  Improved solution reported by Keld Helsgaun (Roskilde University) obtained with LKH-3 code for merging the solution from January, 18 2023 (4373245) with the solution from May 3, 2022 (4373320): Flanders2 (4373244).
  • November, 13 2023 - Proven optimal solution by Zhengzhong You (University of Florida), Yu Yang (University of Florida), Xinshang Wang (Alibaba Group US), and Wotao Yin (Alibaba Group US) using RouteOpt exact solver: X-n294-k50 (47161).
  • October, 25 2023 - Proven optimal VRPTW solutions by João Marcos Pereira Silva and Eduardo Uchoa using VRPSolver with a new cluster branching strategy: C2_2_4 (1695), RC2_2_10 (1989.2).
  • September, 14 2023 - Proven optimal CVRP and VRPTW solutions by João Marcos Pereira Silva and Eduardo Uchoa using VRPSolver with a new cluster branching strategy: RC1_2_9 (3073.3), RC1_2_10 (2990.5), X-n344-k43 (42050), X-n351-k40 (25896), X-n367-k17 (22814), and X-n670-k130 (146332).
  • June, 26 2023 - Improved VRPTW solutions reported by Simen T. Vadseth, Henrik Andersson, Jean-François Cordeau, and Magnus Stålhane: R1_6_4 (15720.8), R1_8_3 (29301.2), R1_8_5 (33494.0), R1_8_10 (30918.3), R2_8_1 (24963.8), R2_8_5 (22795.6), R2_8_8 (12611.6), C1_10_8 (41648.0), R1_10_1 (53026.1), R1_10_2 (48261.6), R1_10_3 (44673.3), R1_10_6 (46928.2), R2_10_4 (17811.4), R2_10_8 (17403.7), RC1_10_1 (45790.7), RC1_10_3 (42121.9), RC1_10_6 (44898.2), RC1_10_7 (44409.0), RC1_10_9 (43858.0), RC2_10_4 (15654.7).
  • June, 5 2023 - Improved VRPTW solutions reported by Niels Wouda, Leon Lan, and Wouter Kool using PyVRP solver: C1_10_3 (40060.0), C2_8_4 (10639.6), R1_4_2 (8873.2), R1_4_3 (7781.6), R1_4_9 (8673.8), R1_6_2 (18519.8), R2_4_10 (5638.1), R2_6_4 (7914.5), R2_6_7 (9770.3), R2_8_10 (19964.2), R2_8_1 (24968.8), R2_8_3 (17229.5), R2_8_4 (13152.8), R2_8_5 (22798.2), R2_8_7 (16351.2), RC1_6_1 (16944.2), RC1_8_1 (29952.8), RC1_8_6 (29148.7), RC1_8_7 (28734.0), RC1_8_8 (28390.0), RC1_8_9 (28331.6), RC2_10_7 (24391.4), RC2_10_8 (23279.8), RC2_8_6 (17190.6), RC2_8_9 (15177.2). 
  • May, 28 2023 - Improved VRPTW solutions reported by Niels Wouda, Leon Lan, and Wouter Kool using PyVRP solver: C2_8_4 (10641.9), R1_6_2 (18554.4), R2_6_7 (9774.1), R2_8_10 (19977.7), RC1_6_1 (16952.3), RC1_8_7 (28781.0), RC2_10_10 (21731.2), RC2_10_7 (24392.2), RC2_6_10 (8973.3).
  • January, 18 2023 -  Improved solutions reported by Jørgen Skålnes, Simen T. Vadseth, Henrik Andersson, and Magnus Stålhane from NTNU using a branch-and-cut embedded matheuristic: Brussels2 (345468), Flanders1 (7240118), Flanders2 (4373245).
  • January, 18 2023 -  Proven optimal VRPTW solutions by João Marcos Pereira Silva and Eduardo Uchoa using VRPSolver with a new cluster branching strategy: C1_10_1 (42444.8), C1_10_5 (42434.8), C1_10_6 (42437.0), C1_6_1 (14076.6), C1_6_2 (13948.3), C1_6_3 (13756.5), C1_6_4 (13538.6), C1_6_5 (14066.8), C1_6_6 (14070.9), C1_6_7 (14066.8), C1_6_8 (13991.2), C1_6_9 (13664.5), C1_8_1 (25156.9), C1_8_5 (25138.6), C1_8_6 (25133.3), C1_8_7 (25127.3). For instance C1_6_3, the optimal solution found was an improved one.
  • January, 5 2023 - Improved solution obtained by Mariá C.V. Nascimento (Universidade Federal de São Paulo) and Vinícius R. Máximo  (Universidade Federal de São Paulo): Flanders2 (4373316).
  • December, 15 2022 -  Improved VRPTW solutions reported by Piotr Sielski, Piotr Cybula, Mariusz Kok, Przemysław Pełka, Marek Rogalski (Otimo, and University of Łódź, Poland): C1_10_2 (41337.8), C1_8_8 (24809.7), C2_8_4 (10650.0), R1_10_1 (53046.5), R1_4_5 (9184.6), R1_6_5 (19294.9), R1_6_9 (18474.1), R1_8_1 (36345.0), R2_10_10 (29840.5), R2_10_6 (29124.7), R2_8_10 (19984.8), R2_8_3 (17234.8), R2_8_7 (16357.5), RC1_8_10 (28168.5), RC1_8_1 (29978.9), RC1_8_2 (28290.1), RC1_8_3 (27447.7), RC1_8_4 (26557.2), RC1_8_5 (29219.9), RC1_8_6 (29194.2), RC1_8_7 (28788.6), RC1_8_8 (28418.1), RC1_8_9 (28347.1), RC2_10_10 (21736.1), RC2_10_3 (19618.1), RC2_10_7 (24395.8), RC2_10_8 (23280.2), RC2_8_10 (14370.9), RC2_8_6 (17195.1), RC2_8_9 (15183.0).
  • October, 10 2022 -  Improved VRPTW solutions reported by Piotr Sielski, Piotr Cybula, Mariusz Kok, Przemysław Pełka, Marek Rogalski (Otimo, and University of Łódź, Poland): C1_6_10 (13617.5), C1_8_10 (24026.7), C2_10_4 (15459.5), R1_10_1 (53046.6), R1_4_3 (7784.3), R1_6_5 (19301.3), R1_6_9 (18476.4), R1_8_1 (36380.8), R2_10_7 (23102.2), R2_8_4 (13160.8), R2_8_6 (19740.5), RC1_4_5 (8152.3), RC1_6_3 (15181.3), RC1_8_10 (28173.0), RC1_8_2 (28309.4), RC1_8_3 (27451.1), RC1_8_4 (26574.6), RC1_8_5 (29249.9), RC1_8_6 (29198.8), RC1_8_7 (28795.2), RC1_8_8 (28420.9), RC1_8_9 (28356.9), RC2_10_3 (19624.3), RC2_10_9 (22731.6), RC2_6_10 (8974.7), RC2_8_10 (14374.9), RC2_8_2 (16709.5), RC2_8_4 (10969.4).
  • August, 31 2022 - Improved VRPTW solutions reported by Piotr Sielski, Piotr Cybula, Mariusz Kok, Przemysław Pełka, Marek Rogalski (Otimo, and University of Łódź, Poland): C1_10_2 (41352.1), C1_10_8 (41652.1), C1_8_3 (24156.1), C1_8_8 (24810.1), C2_10_9 (16075.4), C2_6_4 (6877.0), C2_6_7 (7491.3), C2_8_4 (10650.3), R1_4_2 (8873.3), R2_10_10 (29850.7), R2_10_1 (36881.0), R2_10_2 (31241.9), R2_10_3 (24399.0), R2_10_5 (34132.8), R2_10_6 (29126.5), R2_10_9 (31990.6), R2_4_8 (4000.1), R2_6_10 (11837.0), R2_6_2 (12976.3), R2_6_5 (13790.2), R2_6_6 (11847.8), R2_6_9 (12736.8), R2_8_10 (19985.6), R2_8_1 (24969.8), R2_8_3 (17235.1), R2_8_5 (22801.6), R2_8_6 (19745.2), R2_8_7 (16359.7), R2_8_9 (21282.7), RC1_4_1 (8522.9), RC2_10_1 (28122.6), RC2_10_2 (24248.6), RC2_10_3 (19624.7), RC2_10_5 (25797.5), RC2_10_6 (25782.5), RC2_10_7 (24420.5), RC2_10_8 (23281.2), RC2_6_7 (10289.4), RC2_6_8 (9779.0), RC2_8_1 (19201.3), RC2_8_2 (16710.1), RC2_8_3 (14013.6), RC2_8_6 (17196.6), RC2_8_7 (16362.2), RC2_8_8 (15528.8).
  • August, 8 2022 - Improved VRPTW solution reported by Piotr Sielski, Piotr Cybula, Mariusz Kok, Przemysław Pełka, Marek Rogalski (Otimo, and University of Łódź, Poland): RC1_4_10 (7581.2).
  • August, 8 2022 - Improved solution reported by The-Viet Bui (Singapore Management University): Loggi-n501-k24 (177078).
  • July 5, 2022 - Proven optimal solution by João Marcos Pereira Silva and Eduardo Uchoa using VRPSolver with a new cluster branching strategy: X-n256-k16 (18839).
  • May 3, 2022 - Improved solutions reported by Francesco Cavaliere (University of Bologna, Italy), Matteo Fischetti (University of Padova, Italy), and Keld Helsgaun (Roskilde University, Denmark), obtained using the solver LKHSP: Antwerp2 (291350), Brussels1 (501719), Flanders1 (7240124), Flanders2 (4373320), Loggi-n401-k23 (336903), Loggi-n501-k24 (177176), Loggi-n901-k42 (246301).
  • April 29, 2022 - CVRPLIB now also has benchmarks for the VRP with time windows (VRPTW). The benchmarks of Solomon (1987) and Homberger and Gehring (1999) have been included. Here we assume the convention of the 12th DIMACS Implementation Challenge and recent exact algorithms (Baldacci et al, 2011, Pecin et al, 2017, Pessoa et al, 2020, Sadykov et al, 2020), which is to minimize the total distance, where Euclidean distances are obtained from the location coordinates and then truncated to one decimal place. Some of the current BKSs were found by Thibaut Vidal with UHGS, some others by VRPSolver, whereas most of them were found by participants of the DIMACS challenge in a pre-competition phase as reported here. The BKSs for the hierarchical objective (usually adopted for heuristics in the literature) are already managed by the Transportation Optimization Portal of SINTEF Applied Mathematics.
  • April 6, 2022 - Improved solutions reported by Francesco Cavaliere (University of Bologna, Italy), Matteo Fischetti (University of Padova, Italy), and Keld Helsgaun (Roskilde University, Denmark), obtained using LKH-3 code for merging the previously best solutions with solutions obtained by solver LKHSP: Antwerp2 (291351), Brussels1 (501720), Brussels2 (345481), Flanders1 (7240141), Flanders2 (4373322).
  • March 1, 2022 - New set XML100 (all instances with 100 customers), proposed in "10,000 optimal CVRP solutions for testing machine learning based heuristics" by Queiroga et al. A single zip file contains the instances, the optimal solutions, and the instance generator Python code.
  • February, 9 2022 - Improved solutions obtained in the DIMACS Challenge by Mariá C.V. Nascimento (Universidade Federal de São Paulo), Vinícius R. Máximo  (Universidade Federal de São Paulo), and Jean-François Cordeau (HEC Montréal) with the solver AILS-II: Loggi-n401-k23 (336915), Loggi-n501-k24 ((177351)), Loggi-n901-k42 (246384), ORTEC-n455-k41 (292485), ORTEC-n701-k64 (445543). Improved solution obtained in the DIMACS Challenge by Luca Accorsi (University of Bologna), Francesco Cavaliere (University of Bologna), and Daniele Vigo (University of Bologna) with the solver FSP4D: Golden_12 (1100.67).
  • February, 7 2022 - Proven optimal DCVRP solution by João Marcos Pereira Silva using VRPSolver: CMT13 (1541.14).
  • January, 16 2022 -  Improved solutions reported by Simen T. Vadseth, Henrik Andersson, and Magnus Stålhane from NTNU: Antwerp2 (291353), Brussels1 (501721), Brussels2 (345482), Flanders1(7240144), Flanders2 (4373329), Ghent1 (469531).
  • December, 16 2021 - Improved solutions obtained in the DIMACS Challenge by Solver LKHSP, from Team Vavavuma! (Francesco Cavaliere (University of Bologna), Matteo Fischetti (University of Padova, Italy), and Keld Helsgaun (Roskilde University, Denmark)): Brussels1 (501734), Brussels2 (345485), Flanders1 (7240218), Flanders2 (4373346), Ghent2 (257748), Leuven2 (111391).
  • December, 5 2021 - Improved solution reported by Luca Accorsi (University of Bologna), Francesco Cavaliere (University of Bologna), and Daniele Vigo (University of Bologna): Golden_12 (1101.24).
  • November, 29 2021 - Improved solutions reported by Luca Accorsi (University of Bologna), Francesco Cavaliere (University of Bologna), and Daniele Vigo (University of Bologna): Loggi-n601-k19 (113155), Loggi-n1001-k31 (284356).
  • November, 22 2021 - Improved solutions reported by Simen T. Vadseth, Henrik Andersson, and Magnus Stålhane from NTNU using an improvement matheuristic: Brussels1 (501743), Brussels2 (345496), Flanders1(7240389), Flanders2 (4373440), Ghent2 (257749), Leuven2 (111395).
  • November, 11 2021 - New set of real-world instances contributed to the DIMACS Challenge. Instances Loggi-n401-k23, Loggi-n501-k24, Loggi-n601-k19, Loggi-n601-k42, Loggi-n901-k42, Loggi-n1001-k31, kindly contributed by Loggi, extracted from a large dataset of real vehicle routing and facility location instances. Instances ORTEC-n242-k12, ORTEC-n323-k21, ORTEC-n405-k18, ORTEC-n455-k41, ORTEC-n510-k23, ORTEC-n701-k64, kindly contributed by Wouter Kool (ORTEC).
  • November, 8 2021 - Improved solutions reported by Simen T. Vadseth, Henrik Andersson, and Magnus Stålhane from NTNU using an improvement matheuristic: Brussels2 (345505), Flanders2 (4373569), Ghent2 (257763).
  • October, 21 2021 -  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 -  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 - Proved optimal solutions using VRPSolver:  X-n261-k13 (26558) and X-n856-k95 (88965).
  • January, 30 2021 - 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 - Improved solutions reported by Luca Accorsi and Daniele Vigo (University of Bologna): Ghent2 (257910), Leuven2 (111415).
  • January, 21 2021 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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).
  • July, 30 2020 - Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): Antwerp1 (478019), Antwerp2 (292511), Brussels1 (503350), Brussels2 (348740), Flanders1 (7256400), Flanders2 (4402841), Ghent1 (470306), Ghent2 (259486), Leuven1 (193059), Leuven2 (111794).
  • July, 25 2020 - Improved solution reported by Ben Johnson (Canfield Research):  Brussels2 (348861).
  • July, 24 2020 - Improved solution reported by Ben Johnson (Canfield Research):  Brussels1 (503377).
  • July, 23 2020 - Improved solutions reported by Ben Johnson (Canfield Research):  Flanders1 (7256462), Ghent2 (259594).
  • July, 17 2020 - Improved solution reported by Ben Johnson (Canfield Research): Leuven2 (111810).
  • July, 2 2020 - Improved solutions by Eduardo Queiroga, Eduardo Uchoa, and Ruslan Sadykov through a POPMUSIC heuristic using exact VRPSolver: X-n303-k21 (21738), X-n344-k43 (42050), X-n351-k40 (25896), X-n384-k52 (65940), X-n536-k96 (94868), X-n586-k159 (190316), X-n599-k92 (108451), X-n627-k43 (62173).
  • June, 17 2020 - Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): Antwerp1 (478091), Antwerp2 (292597), Brussels1 (503407), Brussels2 (349602), Flanders1 (7256529), Flanders2 (4405678), Ghent1 (470329), Ghent2 (259712), Leuven1 (193092), Leuven2 (111860).
  • June, 5 2020 - Improved solutions reported by Ante Galic from Mireo d.d. (Croatia): Antwerp1 (478286), Antwerp2 (293083), Brussels1 (503998), Brussels2 (351518), Flanders1 (7261371), Flanders2 (4417165), Ghent1 (470554), Ghent2 (260467), Leuven1 (193201), Leuven2 (112261).
  • May, 18 2020 - Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): Antwerp1 (478674), Antwerp2 (293802), Brussels1 (504023), Brussels2 (352012), Flanders1 (7270362), Flanders2 (4455217), Ghent1 (470818), Ghent2 (260553), Leuven1 (193220), Leuven2 (112280), X-n573-k30 (50673), X-n766-k71 (114456), X-n876-k59 (99303), X-n895-k37 (53928), X-n936-k151 (132812), X-n1001-k43 (72369).
  • May, 8 2020 - Improved solutions by Eduardo Queiroga, Eduardo Uchoa, and Ruslan Sadykov through a POPMUSIC heuristic using exact VRPSolver: X-n303-k21 (21739), X-n351-k40 (25917), X-n411-k19 (19712), X-n429-k61 (65467), X-n449-k29 (55254), X-n480-k70 (89449), X-n491-k59 (66487), X-n536-k96 (94872), X-n573-k30 (50678), X-n586-k159 (190357), X-n627-k43 (62178), X-n641-k35 (63705), X-n685-k75 (68225), X-n701-k44 (81923), X-n716-k35 (43387), X-n749-k98 (77314), X-n766-k71 (114487), X-n783-k48 (72394), X-n819-k171 (158121), X-n837-k142 (193737), X-n856-k95 (88990), X-n876-k59 (99309), X-n895-k37 (53930), X-n936-k151 (132813), X-n957-k87 (85469), X-n979-k58 (118988), X-n1001-k43 (72370).
  • May, 5 2020 - Improved solution reported by Van Hanh Pham (VNU-UET, ORLab team), Duc Dong Do (VNU-UET, ORLab team), and Minh Hoàng Hà (Phenikaa University, ORLab team): Flanders1 (7272223).
  • May, 3 2020 - Improved solutions reported by Francesco Cavaliere, Emilio Bendotti, and Matteo Fischetti (University of Padova): Antwerp1 (478775), Antwerp2 (293953), Brussels1 (504175), Brussels2 (352658), Flanders1 (7272444), Flanders2 (4469477), Ghent1 (470902), Ghent2 (260987), Leuven1 (193244), Leuven2 (112378), X-n351-k40 (25919), X-n384-k52 (65941), X-n536-k96 (94921), X-n561-k42 (42717), X-n573-k30 (50708), X-n641-k35 (63723), X-n670-k130 (146332), X-n685-k75 (68245), X-n716-k35 (43412), X-n819-k171 (158247), X-n876-k59 (99330), X-n895-k37 (53935), X-n936-k151 (132881), X-n957-k87 (85474), X-n979-k58 (118996), X-n1001-k43 (72397).
  • January, 17 2020 -  Improved solutions by Eduardo Queiroga through a POPMUSIC heuristic using exact VRPSolver: X-n336-k84 (139111), X-n480-k70 (89457), X-n491-k59 (66503), X-n502-k39 (69226), X-n536-k96 (94950), X-n586-k159 (190368), X-n599-k92 (108455), X-n613-k62 (59545), X-n670-k130 (146446), X-n685-k75 (68252), X-n733-k159 (136190), X-n749-k98 (77353), X-n766-k71 (114501), X-n819-k171 (158249), X-n837-k142 (193752), X-n856-k95 (88997), X-n916-k207 (329179), X-n936-k151 (132907).
  • July, 14 2019 -  Improved solutions to the very large Belgium instances by Ante Galic: Antwerp1 (479021), Antwerp2 (294319), Brussels1 (504392), Brussels2 (353285), Flanders1 (7273695), Flanders2 (4480972), Ghent1 (471084), Ghent2 (261676), Leuven1 (193343), Leuven2 (112751).
  • April, 10 2019 - Improved solutions to the very large Belgium instances by Keld Helsgaun using LKH-3: Antwerp1 (480140), Antwerp2 (294940), Brussels1 (505755), Brussels2 (354789), Flanders1 (7279086), Flanders2 (4499188), Ghent1 (472202), Ghent2 (263506), Leuven1 (194095), Leuven2 (112998).
  • March, 1st 2019 - Improved and proven optimal solutions by Pessoa et al. (2019): X-n284-k15 (20215), X-n322-k28 (29834), X-n393-k38 (38260), X-n469-k138 (221824) and X-n548-k50 (86700).
  • February, 28th 2019 - Proved optimal DCVRP solutions by Sadykov et al. (2017): CMT6 (555.43), CMT7 (909.68), CMT8 (865.94), CMT9 (1162.55), CMT10 (1395.85), CMT14 (866.37).
  • January, 22th 2019- New set of very large instances (3,000 to 30,000 customers, from Belgium) by Arnold, Gendreau and Sörensen.
  • September, 15th 2018- Improved solutions reported by Vu Hoang Vuong Nguyen, Duc Dong Do, Hoang Duc Nguyen, and Minh Hoàng Hà (Vietnam National University ORLab): X-n573-k30(50717), X-670-k130(146476), X-837-k142(193809) and X-n1001-k43(72402).
  • February, 23rd 2018- Improved solutions reported by Keld Helsgaun using LKH-3: X-n524-k153 (154593), X-n573-k30 (50718), X-n599-k92 (108489), X-n819-k171 (158265), X-n837-k142 (193810), X-n856-k95 (89002), X-n936-k151 (132923), X-n957-k87 (85478) and X-n1001-k43 (72403).
  • August, 14th 2017 - Improved solutions reported (Toffolo, Vidal, Wauters (2017), Heuristics for vehicle routing problems: Sequence or set optimization?, to appear as a working paper): X-n294-k50 (47161), X-n322-k28 (29834), X-n327-k20 (27532), X-n344-k43 (42056), X-n393-k38 (38260) and X-n459-k26 (24145).
  • November, 23rd 2016 - Improved solutions reported by Jan Christiaens obtained using ASB-RR: X-n359-k29 (51505), X-n384-k52 (65943), X-n401-k29 (66187), X-n449-k29 (55269), X-n459-k26 (24173), X-n491-k59 (66510), X-n502-k39 (69230), X-n536-k96 (94988), X-n561-k42 (42722), X-n599-k92 (108490), X-n627-k43 (62210), X-n670-k130 (146451), X-n685-k75 (68261), X-n701-k44 (81934), X-n716-k35 (43414), X-n749-k98 (77365), X-n766-k71 (114525), X-n783-k48 (72445), X-n801-k40 (73331), X-n837-k142 (193813), X-n876-k59 (99331), X-n895-k37 (53946), X-n916-k207 (329247), X-n936-k151 (132926) and X-n957-k87 (85482).
  • November, 6th 2016 - Improved solution to X-n256-k16 (18839) reported by Túlio Toffolo and Thibaut Vidal. This contradicts a previous claim that a solution with value 18880 was optimal. After investigation, it was found that a typo in a script made the BCP method (Pecin et al., 2014) to be run with a minimum of 17 routes. The improving solution has 16 routes. The status of that instance is also corrected to "open".
  • April, 25th 2016 - Proven optimal solutions by the BCP method (Pecin et al., 2014): X-n214-k11 (10856) and X-n233-k16 (19230).
  • April, 4th 2016 -Improved and proven optimal solutions by the BCP method (Pecin et al., 2014): X-n331-k15 (31102) and X-n439-k37 (36391).
  • April, 1st 2016 - Improved solutions reported by Jan Christiaens: X-n322-k28 (29848), X-n336-k84 (139135), X-n344-k43 (42068), X-n351-k40 (25928), X-n384-k52 (65981), X-n401-k29 (66202), X-n449-k29 (55302), X-n459-k26 (24179), X-n480-k70 (89458), X-n491-k59 (66520), X-n502-k39 (69232), X-n536-k96 (94991), X-n548-k50 (86701), X-n573-k30 (50719), X-n586-k159 (190423), X-n599-k92 (108541), X-n613-k62 (59556), X-n627-k43 (62217), X-n641-k35 (63737), X-n670-k130 (146477), X-n685-k75 (68276), X-n701-k44 (81962), X-n716-k35 (43441), X-n733-k159 (136250), X-n749-k98 (77402), X-n766-k71 (114534), X-n783-k48 (72453), X-n801-k40 (73344), X-n819-k171 (158267), X-n837-k142 (193836), X-n856-k95 (89007), X-n876-k59 (99360), X-n895-k37 (53948), X-n916-k207 (329299), X-n957-k87 (85517), X-n979-k58 (119008) and X-n1001-k43 (72404).
  • June, 22nd 2015 - Improved solutions reported by Jan Christiaens: X-n322-k28 (29854), X-n336-k84 (139165), X-n344-k43 (42073), X-n351-k40 (25936), X-n384-k52 (66021), X-n401-k29 (66219), X-n480-k70 (89488), X-n491-k59 (66523), X-n536-k96 (95062), X-n561-k42 (42754), X-n573-k30 (50726), X-n586-k159 (190454), X-n599-k92 (108600), X-n627-k43 (62264), X-n641-k35 (63760), X-n670-k130 (146570), X-n685-k75 (68291), X-n701-k44 (81997), X-n716-k35 (43491), X-n733-k159 (136313), X-n749-k98 (77423), X-n766-k71 (114566), X-n783-k48 (72547), X-n801-k40 (73367), X-n819-k171 (158298), X-n837-k142 (193933), X-n856-k95 (89040), X-n876-k59 (99424), X-n895-k37 (54030), X-n916-k207 (329394), X-n936-k151 (132946), X-n957-k87 (85566), X-n979-k58 (119072) and X-n1001-k43 (72477).
  • April, 10th 2015 - Proven optimal solutions by the BCP method (Pecin et al., 2014): G13 (857.19), X-n190-k8 (16980).
  • January, 5th 2015 - Improved and proven optimal BKSs by the BCP method (Pecin et al., 2014): G20 (1817.59), X-n289-k60 (95151).
  • January, 5th 2015 - Improved solutions by the UHGS method (Vidal et al., 2014): X-n327-k20 (27546), X-n336-k84 (139172), X-n344-k43 (42092), X-n429-k61 (65483), X-n449-k29(55355), X-n586-k159 (190491), X-n599-k92 (108736), X-n613-k62 (59584), X-n685-k75 (68415), X-n701-k44 (82254), X-n716-k35 (43517), X-n783-k48 (72715), X-n801-k40 (73564), X-n819-k171 (158558), X-n837-k142 (194187), X-n876-k59 (99653), X-n895-k37 (54071), X-n916-k207 (329752), X-n936-k151 (133046), X-n957-k87 (85663) and X-n1001-k43 (72719).
  • November, 20th 2014 - Improved solution values by the CPM method from the paper (Jin et al., 2014): G4 (590.00), G10 (735.66), G11 (912.03), G12 (1101.50), G15 (1337.87) and G16 (1611.56). We could not obtain those solutions yet!
  • October, 16th 2014 - Official release of CVRPLIB. The status of each instance was obtained either from the literature or from new experiments with state-of-the-art algorithms, as described in Uchoa et al. (2017).