Fatal
Serious
Slight
Uncategorised
| Date | Local Authority | Vehicles | Casualties | Severity |
|---|---|---|---|---|
| Mon 18 Jan 1999 | East Hertfordshire | 2 | 1 | Slight |
| Sat 23 Jan 1999 | East Hertfordshire | 1 | 1 | Serious |
| Tue 16 Feb 1999 | Welwyn Hatfield | 2 | 1 | Slight |
| Mon 22 Feb 1999 | East Hertfordshire | 3 | 1 | Slight |
| Mon 19 Apr 1999 | East Hertfordshire | 2 | 1 | Serious |
| Tue 20 Apr 1999 | East Hertfordshire | 2 | 1 | Slight |
| Sat 8 May 1999 | East Hertfordshire | 1 | 2 | Slight |
| Sun 23 May 1999 | East Hertfordshire | 3 | 2 | Slight |
| Sat 12 Jun 1999 | East Hertfordshire | 2 | 1 | Slight |
| Mon 21 Jun 1999 | Welwyn Hatfield | 2 | 2 | Slight |
| Sun 4 Jul 1999 | Welwyn Hatfield | 1 | 5 | Serious |
| Thu 12 Aug 1999 | Welwyn Hatfield | 2 | 1 | Slight |
| Fri 13 Aug 1999 | East Hertfordshire | 2 | 2 | Slight |
| Mon 16 Aug 1999 | East Hertfordshire | 2 | 2 | Slight |
| Tue 24 Aug 1999 | East Hertfordshire | 3 | 1 | Slight |
| Fri 10 Sep 1999 | East Hertfordshire | 3 | 1 | Slight |
| Wed 22 Sep 1999 | Welwyn Hatfield | 1 | 1 | Serious |
| Mon 15 Nov 1999 | East Hertfordshire | 2 | 2 | Slight |
| Mon 22 Nov 1999 | East Hertfordshire | 1 | 1 | Slight |
| Sun 5 Dec 1999 | East Hertfordshire | 2 | 1 | Slight |
| Sat 11 Dec 1999 | East Hertfordshire | 2 | 1 | Slight |
| Mon 20 Dec 1999 | Welwyn Hatfield | 1 | 1 | Serious |
| Thu 23 Dec 1999 | Welwyn Hatfield | 2 | 2 | Slight |