Fatal
Serious
Slight
Uncategorised
| Date | Local Authority | Vehicles | Casualties | Severity |
|---|---|---|---|---|
| Tue 2 Jan 1990 | Hertsmere | 1 | 2 | Slight |
| Tue 2 Jan 1990 | Hertsmere | 2 | 1 | Slight |
| Thu 4 Jan 1990 | Harrow | 2 | 1 | Slight |
| Sat 6 Jan 1990 | Harrow | 1 | 1 | Slight |
| Wed 10 Jan 1990 | Harrow | 2 | 1 | Serious |
| Wed 10 Jan 1990 | Harrow | 2 | 1 | Serious |
| Mon 15 Jan 1990 | Harrow | 2 | 1 | Slight |
| Tue 16 Jan 1990 | Harrow | 1 | 1 | Slight |
| Thu 18 Jan 1990 | Harrow | 1 | 2 | Slight |
| Wed 31 Jan 1990 | Harrow | 1 | 2 | Slight |
| Wed 31 Jan 1990 | Harrow | 1 | 1 | Fatal |
| Sat 3 Feb 1990 | Harrow | 1 | 1 | Slight |
| Mon 5 Feb 1990 | Harrow | 1 | 1 | Serious |
| Mon 5 Feb 1990 | Harrow | 1 | 1 | Slight |
| Thu 8 Feb 1990 | Harrow | 2 | 1 | Serious |
| Fri 2 Mar 1990 | Harrow | 2 | 1 | Serious |
| Thu 8 Mar 1990 | Harrow | 1 | 1 | Slight |
| Fri 9 Mar 1990 | Harrow | 2 | 1 | Slight |
| Sun 18 Mar 1990 | Harrow | 2 | 1 | Slight |
| Mon 19 Mar 1990 | Harrow | 2 | 1 | Slight |
| Tue 20 Mar 1990 | Harrow | 1 | 1 | Slight |
| Wed 21 Mar 1990 | Harrow | 2 | 3 | Serious |
| Thu 22 Mar 1990 | Harrow | 2 | 1 | Slight |
| Sat 24 Mar 1990 | Harrow | 1 | 1 | Slight |
| Wed 28 Mar 1990 | Harrow | 2 | 2 | Serious |
| Thu 29 Mar 1990 | Harrow | 2 | 1 | Slight |
| Tue 3 Apr 1990 | Harrow | 1 | 1 | Slight |
| Fri 6 Apr 1990 | Harrow | 1 | 1 | Slight |
| Fri 13 Apr 1990 | Harrow | 2 | 3 | Slight |
| Sat 14 Apr 1990 | Harrow | 1 | 1 | Slight |
| Mon 23 Apr 1990 | Harrow | 1 | 1 | Slight |
| Fri 27 Apr 1990 | Harrow | 1 | 1 | Slight |
| Sat 28 Apr 1990 | Harrow | 1 | 1 | Slight |
| Sat 28 Apr 1990 | Harrow | 1 | 1 | Slight |
| Mon 30 Apr 1990 | Harrow | 1 | 1 | Slight |
| Thu 3 May 1990 | Harrow | 3 | 2 | Slight |
| Fri 4 May 1990 | Harrow | 2 | 1 | Slight |
| Fri 11 May 1990 | Harrow | 3 | 2 | Slight |
| Sun 13 May 1990 | Harrow | 1 | 1 | Slight |
| Wed 16 May 1990 | Harrow | 2 | 2 | Slight |
| Fri 18 May 1990 | Harrow | 2 | 2 | Serious |
| Sat 19 May 1990 | Harrow | 1 | 1 | Slight |
| Tue 22 May 1990 | Harrow | 2 | 1 | Slight |
| Thu 31 May 1990 | Harrow | 2 | 1 | Slight |
| Thu 31 May 1990 | Harrow | 2 | 1 | Serious |
| Fri 1 Jun 1990 | Harrow | 2 | 2 | Slight |
| Sat 2 Jun 1990 | Harrow | 2 | 1 | Serious |
| Thu 7 Jun 1990 | Hertsmere | 3 | 1 | Slight |
| Sat 9 Jun 1990 | Harrow | 2 | 1 | Slight |
| Tue 12 Jun 1990 | Harrow | 1 | 1 | Slight |
| Tue 12 Jun 1990 | Harrow | 1 | 1 | Slight |
| Fri 15 Jun 1990 | Harrow | 2 | 1 | Slight |
| Fri 22 Jun 1990 | Hertsmere | 1 | 1 | Slight |
| Wed 27 Jun 1990 | Harrow | 1 | 1 | Slight |
| Wed 4 Jul 1990 | Harrow | 2 | 1 | Serious |
| Fri 6 Jul 1990 | Harrow | 2 | 1 | Slight |
| Thu 12 Jul 1990 | Harrow | 2 | 2 | Slight |
| Fri 13 Jul 1990 | Hertsmere | 3 | 1 | Slight |
| Mon 16 Jul 1990 | Harrow | 3 | 1 | Slight |
| Sun 29 Jul 1990 | Harrow | 2 | 1 | Slight |
| Wed 1 Aug 1990 | Harrow | 2 | 1 | Serious |
| Thu 2 Aug 1990 | Harrow | 2 | 1 | Slight |
| Thu 2 Aug 1990 | Brent | 2 | 1 | Slight |
| Tue 7 Aug 1990 | Harrow | 1 | 2 | Slight |
| Sun 12 Aug 1990 | Harrow | 1 | 2 | Serious |
| Sat 18 Aug 1990 | Harrow | 2 | 1 | Slight |
| Thu 23 Aug 1990 | Harrow | 2 | 1 | Slight |
| Wed 29 Aug 1990 | Harrow | 2 | 1 | Slight |
| Tue 4 Sep 1990 | Harrow | 2 | 1 | Slight |
| Tue 4 Sep 1990 | Harrow | 1 | 1 | Slight |
| Thu 6 Sep 1990 | Harrow | 2 | 1 | Slight |
| Wed 12 Sep 1990 | Harrow | 2 | 1 | Slight |
| Wed 12 Sep 1990 | Harrow | 2 | 1 | Slight |
| Sat 15 Sep 1990 | Harrow | 2 | 2 | Serious |
| Sat 29 Sep 1990 | Harrow | 2 | 2 | Serious |
| Fri 5 Oct 1990 | Harrow | 2 | 1 | Slight |
| Sat 6 Oct 1990 | Harrow | 3 | 1 | Slight |
| Sat 6 Oct 1990 | Harrow | 2 | 2 | Serious |
| Thu 11 Oct 1990 | Harrow | 3 | 1 | Slight |
| Sat 13 Oct 1990 | Harrow | 2 | 2 | Serious |
| Sun 14 Oct 1990 | Harrow | 2 | 2 | Slight |
| Thu 18 Oct 1990 | Harrow | 1 | 1 | Slight |
| Mon 22 Oct 1990 | Harrow | 1 | 1 | Slight |
| Wed 24 Oct 1990 | Harrow | 1 | 1 | Slight |
| Thu 1 Nov 1990 | Harrow | 1 | 1 | Serious |
| Sun 4 Nov 1990 | Harrow | 1 | 1 | Slight |
| Fri 9 Nov 1990 | Harrow | 1 | 1 | Slight |
| Sat 10 Nov 1990 | Harrow | 3 | 1 | Slight |
| Mon 12 Nov 1990 | Harrow | 1 | 1 | Slight |
| Thu 15 Nov 1990 | Harrow | 2 | 1 | Slight |
| Thu 15 Nov 1990 | Harrow | 2 | 1 | Slight |
| Fri 16 Nov 1990 | Harrow | 2 | 2 | Slight |
| Mon 19 Nov 1990 | Harrow | 2 | 1 | Slight |
| Tue 20 Nov 1990 | Harrow | 2 | 1 | Slight |
| Fri 23 Nov 1990 | Harrow | 1 | 1 | Slight |
| Fri 30 Nov 1990 | Harrow | 1 | 1 | Slight |
| Tue 4 Dec 1990 | Harrow | 3 | 1 | Slight |
| Wed 5 Dec 1990 | Harrow | 1 | 1 | Slight |
| Fri 7 Dec 1990 | Harrow | 2 | 1 | Slight |
| Mon 10 Dec 1990 | Harrow | 2 | 1 | Slight |
| Mon 17 Dec 1990 | Harrow | 2 | 1 | Slight |
| Thu 20 Dec 1990 | Harrow | 1 | 1 | Slight |
| Fri 21 Dec 1990 | Harrow | 2 | 1 | Slight |
| Mon 24 Dec 1990 | Harrow | 1 | 1 | Serious |
| Sun 30 Dec 1990 | Harrow | 2 | 1 | Serious |