Northamptonshire was an English County. It was abolished in March 2021.
| Year | All Motor Vehicles | Cars and Taxis | Road Network Total Length |
|---|---|---|---|
| 2000 | 4,685,600,000 | 3,634,700,000 | 2,784.2 miles (4,480.8 km) |
| 2001 | 4,794,900,000 | 3,717,800,000 | 2,788.9 miles (4,488.3 km) |
| 2002 | 5,006,600,000 | 3,896,100,000 | 2,793.7 miles (4,496.0 km) |
| 2003 | 5,198,800,000 | 4,045,000,000 | 2,798.5 miles (4,503.8 km) |
| 2004 | 5,301,900,000 | 4,070,800,000 | 2,815.6 miles (4,531.3 km) |
| 2005 | 5,211,200,000 | 3,983,200,000 | 2,821.7 miles (4,541.2 km) |
| 2006 | 5,300,900,000 | 4,040,900,000 | 2,816.1 miles (4,532.0 km) |
| 2007 | 5,345,400,000 | 4,059,600,000 | 2,744.0 miles (4,416.0 km) |
| 2008 | 5,247,800,000 | 4,007,000,000 | 2,750.5 miles (4,426.4 km) |
| 2009 | 5,208,600,000 | 4,018,500,000 | 2,793.5 miles (4,495.7 km) |
| 2010 | 5,181,100,000 | 3,984,000,000 | 2,804.2 miles (4,512.9 km) |
| 2011 | 5,112,600,000 | 3,955,100,000 | 2,809.7 miles (4,521.8 km) |
| 2012 | 5,201,300,000 | 4,000,800,000 | 2,814.9 miles (4,530.1 km) |
| 2013 | 5,233,000,000 | 4,015,900,000 | 2,822.2 miles (4,541.9 km) |
| 2014 | 5,364,000,000 | 4,097,300,000 | 2,827.7 miles (4,550.8 km) |
| 2015 | 5,494,700,000 | 4,172,100,000 | 2,840.0 miles (4,570.6 km) |
| 2016 | 5,616,300,000 | 4,262,400,000 | 2,866.4 miles (4,613.0 km) |
| 2017 | 5,745,900,000 | 4,336,400,000 | 2,880.4 miles (4,635.6 km) |
| 2018 | 5,862,600,000 | 4,412,800,000 | 2,893.1 miles (4,656.0 km) |
| 2019 | 5,992,200,000 | 4,538,800,000 | 2,913.6 miles (4,689.0 km) |
| 2020 | 4,703,400,000 | 3,372,400,000 | 2,942.9 miles (4,736.1 km) |