15-Year Race for Better Tours
Progress in the value of the best known tour for pla85900 is recorded in the following table, together with the research team and the method used to obtain the new record results.
| Date |
Tour Length |
Research Team |
Method |
|
| 07.06.1991 |
142,514,146 |
David S. Johnson |
Iterated Lin-Kernighan |
|
|
| 29.03.1996 |
142,487,006 |
Concorde |
Tour Merging |
|
|
| 23.09.1997 |
142,482,068 |
Concorde |
Tour Merging |
|
|
| 14.10.1998 |
142,416,327 |
Keld Helsgaun |
LKH |
|
|
| 22.10.1999 |
142,409,553 |
Concorde |
Tour Merging |
|
|
| 18.06.2001 |
142,406,493 |
Keld Helsgaun |
LKH |
|
|
| 27.06.2001 |
142,405,532 |
Keld Helsgaun |
LKH |
|
|
| 31.08.2001 |
142,395,130 |
Concorde |
Tour Merging with LKH |
|
|
| 14.12.2001 |
142,393,738 |
Keld Helsgaun |
LKH |
|
|
| 15.09.2002 |
142,385,237 |
Hisao Tamaki |
Approximate Tour Merging |
|
|
| 12.12.2002 |
142,383,704 |
Keld Helsgaun |
LKH |
|
|
| 19.03.2003 |
142,383,467 |
Nguyen Dinh Hung |
Hybrid Genetic Algorithm |
|
|
| 28.04.2003 |
142,383,189 |
Keld Helsgaun |
LKH |
|
|
| 23.12.2003 |
142,383,011 |
Keld Helsgaun |
LKH |
|
|
| 02.05.2004 |
142,382,641 |
Keld Helsgaun |
LKH |