Fatal
Serious
Slight
Uncategorised
| Date | Local Authority | Vehicles | Casualties | Severity |
|---|---|---|---|---|
| Mon 2 Jan 1989 | North Hertfordshire | 2 | 1 | Slight |
| Wed 4 Jan 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Thu 19 Jan 1989 | Welwyn Hatfield | 3 | 2 | Slight |
| Thu 19 Jan 1989 | Welwyn Hatfield | 1 | 1 | Slight |
| Wed 1 Feb 1989 | Welwyn Hatfield | 2 | 1 | Serious |
| Wed 15 Feb 1989 | North Hertfordshire | 3 | 2 | Serious |
| Sun 19 Feb 1989 | Welwyn Hatfield | 2 | 2 | Serious |
| Wed 22 Feb 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Fri 24 Feb 1989 | Welwyn Hatfield | 2 | 1 | Serious |
| Fri 24 Feb 1989 | North Hertfordshire | 2 | 2 | Serious |
| Sat 25 Feb 1989 | Welwyn Hatfield | 1 | 2 | Slight |
| Tue 28 Feb 1989 | Welwyn Hatfield | 1 | 1 | Slight |
| Thu 2 Mar 1989 | Hertsmere | 2 | 2 | Slight |
| Mon 13 Mar 1989 | Stevenage | 2 | 1 | Slight |
| Mon 20 Mar 1989 | North Hertfordshire | 2 | 2 | Serious |
| Fri 31 Mar 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Wed 5 Apr 1989 | Welwyn Hatfield | 1 | 1 | Slight |
| Mon 17 Apr 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Sat 22 Apr 1989 | Welwyn Hatfield | 1 | 1 | Serious |
| Sun 23 Apr 1989 | Hertsmere | 2 | 1 | Slight |
| Tue 25 Apr 1989 | North Hertfordshire | 2 | 2 | Serious |
| Wed 3 May 1989 | Welwyn Hatfield | 2 | 2 | Slight |
| Sat 6 May 1989 | Hertsmere | 2 | 3 | Slight |
| Sun 7 May 1989 | Welwyn Hatfield | 1 | 1 | Fatal |
| Wed 10 May 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Sat 13 May 1989 | Welwyn Hatfield | 1 | 1 | Serious |
| Thu 25 May 1989 | Stevenage | 2 | 1 | Slight |
| Fri 26 May 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Fri 26 May 1989 | North Hertfordshire | 2 | 1 | Slight |
| Thu 1 Jun 1989 | North Hertfordshire | 1 | 1 | Fatal |
| Fri 2 Jun 1989 | North Hertfordshire | 2 | 2 | Slight |
| Mon 5 Jun 1989 | Welwyn Hatfield | 3 | 1 | Serious |
| Thu 8 Jun 1989 | Stevenage | 2 | 1 | Slight |
| Wed 14 Jun 1989 | Welwyn Hatfield | 3 | 3 | Fatal |
| Thu 15 Jun 1989 | Stevenage | 2 | 1 | Slight |
| Mon 10 Jul 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Sun 16 Jul 1989 | Hertsmere | 2 | 1 | Slight |
| Sun 30 Jul 1989 | Welwyn Hatfield | 1 | 1 | Slight |
| Sat 5 Aug 1989 | Hertsmere | 1 | 1 | Slight |
| Mon 7 Aug 1989 | Welwyn Hatfield | 1 | 1 | Slight |
| Mon 7 Aug 1989 | Welwyn Hatfield | 2 | 2 | Serious |
| Tue 12 Sep 1989 | Welwyn Hatfield | 2 | 2 | Slight |
| Wed 13 Sep 1989 | North Hertfordshire | 2 | 1 | Serious |
| Thu 14 Sep 1989 | Welwyn Hatfield | 1 | 1 | Slight |
| Fri 15 Sep 1989 | North Hertfordshire | 1 | 1 | Slight |
| Fri 15 Sep 1989 | North Hertfordshire | 1 | 1 | Slight |
| Wed 20 Sep 1989 | North Hertfordshire | 2 | 2 | Slight |
| Sat 23 Sep 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Sun 24 Sep 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Sat 14 Oct 1989 | Stevenage | 3 | 1 | Slight |
| Thu 26 Oct 1989 | North Hertfordshire | 3 | 2 | Slight |
| Fri 27 Oct 1989 | Welwyn Hatfield | 2 | 1 | Serious |
| Thu 2 Nov 1989 | Welwyn Hatfield | 3 | 1 | Slight |
| Thu 2 Nov 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Fri 3 Nov 1989 | Stevenage | 2 | 1 | Slight |
| Mon 6 Nov 1989 | Stevenage | 1 | 1 | Fatal |
| Sat 11 Nov 1989 | Welwyn Hatfield | 1 | 1 | Slight |
| Sat 11 Nov 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Fri 17 Nov 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Thu 23 Nov 1989 | Welwyn Hatfield | 2 | 2 | Slight |
| Wed 29 Nov 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Mon 4 Dec 1989 | North Hertfordshire | 1 | 1 | Serious |
| Tue 5 Dec 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Wed 20 Dec 1989 | Welwyn Hatfield | 2 | 1 | Slight |
| Fri 22 Dec 1989 | Stevenage | 3 | 1 | Slight |
| Tue 26 Dec 1989 | Welwyn Hatfield | 2 | 3 | Slight |
| Thu 28 Dec 1989 | Hertsmere | 1 | 1 | Serious |