Plymouth is an English Unitary Authority.
| Year | All Motor Vehicles | Cars and Taxis | Road Network Total Length |
|---|---|---|---|
| 2000 | 795,100,000 | 664,200,000 | 496.9 miles (799.7 km) |
| 2001 | 798,700,000 | 664,500,000 | 498.2 miles (801.8 km) |
| 2002 | 849,900,000 | 708,200,000 | 499.6 miles (804.0 km) |
| 2003 | 871,900,000 | 721,900,000 | 500.9 miles (806.1 km) |
| 2004 | 881,000,000 | 721,900,000 | 499.3 miles (803.6 km) |
| 2005 | 892,800,000 | 729,000,000 | 499.5 miles (803.8 km) |
| 2006 | 921,200,000 | 755,100,000 | 503.9 miles (810.9 km) |
| 2007 | 923,500,000 | 752,400,000 | 502.4 miles (808.5 km) |
| 2008 | 920,800,000 | 750,200,000 | 501.7 miles (807.4 km) |
| 2009 | 915,700,000 | 747,400,000 | 502.0 miles (807.9 km) |
| 2010 | 890,900,000 | 724,600,000 | 500.7 miles (805.8 km) |
| 2011 | 899,800,000 | 731,000,000 | 502.6 miles (808.8 km) |
| 2012 | 897,000,000 | 728,900,000 | 503.3 miles (810.0 km) |
| 2013 | 886,000,000 | 723,800,000 | 505.2 miles (813.0 km) |
| 2014 | 905,100,000 | 734,400,000 | 506.8 miles (815.6 km) |
| 2015 | 906,000,000 | 732,000,000 | 509.5 miles (820.0 km) |
| 2016 | 926,900,000 | 751,700,000 | 515.2 miles (829.2 km) |
| 2017 | 934,800,000 | 765,800,000 | 518.6 miles (834.5 km) |
| 2018 | 927,600,000 | 759,000,000 | 516.2 miles (830.8 km) |
| 2019 | 956,900,000 | 786,700,000 | 518.9 miles (835.1 km) |
| 2020 | 759,400,000 | 612,700,000 | 520.1 miles (837.0 km) |
| 2021 | 854,200,000 | 689,300,000 | 521.7 miles (839.6 km) |
| 2022 | 964,100,000 | 781,900,000 | 531.8 miles (855.8 km) |
| 2023 | 994,000,000 | 806,000,000 | 532.2 miles (856.6 km) |