Fatal
Serious
Slight
Uncategorised
| Date | Local Authority | Vehicles | Casualties | Severity |
|---|---|---|---|---|
| Fri 8 Jan 1999 | Stevenage | 1 | 1 | Slight |
| Fri 8 Jan 1999 | Stevenage | 1 | 1 | Slight |
| Sat 9 Jan 1999 | East Hertfordshire | 1 | 1 | Slight |
| Sat 9 Jan 1999 | Stevenage | 2 | 2 | Slight |
| Mon 11 Jan 1999 | Stevenage | 3 | 1 | Serious |
| Sun 17 Jan 1999 | Stevenage | 2 | 2 | Slight |
| Mon 18 Jan 1999 | Stevenage | 2 | 1 | Slight |
| Wed 20 Jan 1999 | Stevenage | 2 | 1 | Slight |
| Wed 27 Jan 1999 | East Hertfordshire | 2 | 1 | Slight |
| Wed 27 Jan 1999 | Stevenage | 2 | 1 | Slight |
| Fri 29 Jan 1999 | Stevenage | 2 | 3 | Slight |
| Mon 1 Feb 1999 | North Hertfordshire | 4 | 1 | Slight |
| Mon 1 Feb 1999 | North Hertfordshire | 2 | 1 | Slight |
| Tue 2 Feb 1999 | East Hertfordshire | 1 | 4 | Slight |
| Wed 3 Feb 1999 | Stevenage | 2 | 1 | Slight |
| Wed 3 Feb 1999 | Stevenage | 2 | 1 | Slight |
| Thu 4 Feb 1999 | North Hertfordshire | 2 | 2 | Slight |
| Fri 5 Feb 1999 | East Hertfordshire | 2 | 1 | Slight |
| Sun 7 Feb 1999 | Stevenage | 2 | 2 | Slight |
| Wed 10 Feb 1999 | Stevenage | 2 | 1 | Slight |
| Wed 10 Feb 1999 | Stevenage | 2 | 1 | Slight |
| Mon 15 Feb 1999 | East Hertfordshire | 2 | 1 | Slight |
| Thu 18 Feb 1999 | Stevenage | 1 | 1 | Slight |
| Thu 18 Feb 1999 | Stevenage | 2 | 1 | Slight |
| Tue 23 Feb 1999 | Stevenage | 3 | 1 | Slight |
| Fri 26 Feb 1999 | Stevenage | 2 | 1 | Slight |
| Fri 26 Feb 1999 | Stevenage | 1 | 1 | Slight |
| Fri 12 Mar 1999 | Rotherham | 2 | 1 | Slight |
| Mon 15 Mar 1999 | Stevenage | 2 | 1 | Slight |
| Mon 15 Mar 1999 | Stevenage | 2 | 1 | Slight |
| Wed 17 Mar 1999 | Stevenage | 2 | 1 | Slight |
| Wed 17 Mar 1999 | Stevenage | 2 | 1 | Slight |
| Fri 19 Mar 1999 | Stevenage | 2 | 1 | Slight |
| Mon 22 Mar 1999 | Stevenage | 2 | 2 | Slight |
| Tue 30 Mar 1999 | Stevenage | 1 | 1 | Slight |
| Sat 10 Apr 1999 | Stevenage | 1 | 1 | Slight |
| Sun 11 Apr 1999 | Stevenage | 2 | 1 | Slight |
| Mon 19 Apr 1999 | Stevenage | 2 | 1 | Slight |
| Mon 19 Apr 1999 | Stevenage | 2 | 1 | Slight |
| Tue 20 Apr 1999 | East Hertfordshire | 2 | 1 | Slight |
| Fri 23 Apr 1999 | Stevenage | 2 | 1 | Slight |
| Fri 23 Apr 1999 | Stevenage | 2 | 1 | Slight |
| Sat 24 Apr 1999 | Stevenage | 2 | 1 | Slight |
| Tue 27 Apr 1999 | North Hertfordshire | 4 | 2 | Serious |
| Tue 27 Apr 1999 | East Hertfordshire | 1 | 2 | Serious |
| Sat 1 May 1999 | Stevenage | 2 | 1 | Slight |
| Wed 5 May 1999 | East Hertfordshire | 3 | 1 | Slight |
| Wed 19 May 1999 | East Hertfordshire | 3 | 1 | Slight |
| Fri 21 May 1999 | East Hertfordshire | 2 | 2 | Slight |
| Tue 25 May 1999 | East Hertfordshire | 3 | 3 | Slight |
| Fri 28 May 1999 | Stevenage | 1 | 1 | Slight |
| Fri 28 May 1999 | Stevenage | 1 | 1 | Slight |
| Fri 28 May 1999 | East Hertfordshire | 2 | 1 | Slight |
| Fri 28 May 1999 | Stevenage | 2 | 1 | Slight |
| Tue 8 Jun 1999 | Stevenage | 2 | 1 | Slight |
| Tue 15 Jun 1999 | East Hertfordshire | 3 | 2 | Serious |
| Tue 15 Jun 1999 | Stevenage | 2 | 2 | Slight |
| Tue 22 Jun 1999 | East Hertfordshire | 2 | 1 | Slight |
| Tue 22 Jun 1999 | East Hertfordshire | 2 | 1 | Slight |
| Fri 25 Jun 1999 | Stevenage | 2 | 1 | Slight |
| Tue 29 Jun 1999 | East Hertfordshire | 3 | 1 | Slight |
| Sat 3 Jul 1999 | North Hertfordshire | 2 | 1 | Slight |
| Sun 4 Jul 1999 | East Hertfordshire | 3 | 2 | Slight |
| Fri 16 Jul 1999 | Stevenage | 2 | 3 | Slight |
| Sat 17 Jul 1999 | Stevenage | 2 | 2 | Slight |
| Sun 18 Jul 1999 | North Hertfordshire | 4 | 2 | Slight |
| Sun 18 Jul 1999 | East Hertfordshire | 2 | 1 | Slight |
| Wed 21 Jul 1999 | Stevenage | 2 | 5 | Slight |
| Thu 22 Jul 1999 | Stevenage | 3 | 1 | Slight |
| Fri 23 Jul 1999 | East Hertfordshire | 2 | 1 | Slight |
| Fri 23 Jul 1999 | East Hertfordshire | 2 | 1 | Slight |
| Sun 25 Jul 1999 | Stevenage | 1 | 1 | Slight |
| Mon 26 Jul 1999 | Stevenage | 2 | 1 | Slight |
| Tue 3 Aug 1999 | Stevenage | 2 | 1 | Slight |
| Fri 6 Aug 1999 | Stevenage | 2 | 1 | Slight |
| Sat 7 Aug 1999 | Stevenage | 3 | 2 | Slight |
| Sun 8 Aug 1999 | East Hertfordshire | 2 | 1 | Slight |
| Tue 10 Aug 1999 | Stevenage | 2 | 1 | Slight |
| Tue 10 Aug 1999 | Stevenage | 2 | 1 | Slight |
| Thu 19 Aug 1999 | Stevenage | 2 | 1 | Slight |
| Fri 20 Aug 1999 | Stevenage | 2 | 1 | Slight |
| Wed 1 Sep 1999 | Stevenage | 3 | 1 | Slight |
| Wed 1 Sep 1999 | Stevenage | 2 | 1 | Slight |
| Thu 2 Sep 1999 | Stevenage | 2 | 4 | Slight |
| Wed 8 Sep 1999 | Stevenage | 2 | 1 | Slight |
| Mon 13 Sep 1999 | North Hertfordshire | 2 | 1 | Slight |
| Tue 14 Sep 1999 | North Hertfordshire | 3 | 1 | Slight |
| Mon 20 Sep 1999 | East Hertfordshire | 1 | 1 | Slight |
| Tue 21 Sep 1999 | Stevenage | 2 | 1 | Slight |
| Tue 21 Sep 1999 | Stevenage | 2 | 1 | Slight |
| Wed 22 Sep 1999 | Stevenage | 2 | 1 | Slight |
| Thu 23 Sep 1999 | North Hertfordshire | 3 | 1 | Serious |
| Thu 30 Sep 1999 | Stevenage | 2 | 3 | Slight |
| Thu 30 Sep 1999 | Stevenage | 2 | 3 | Slight |
| Sat 2 Oct 1999 | Stevenage | 3 | 2 | Slight |
| Tue 5 Oct 1999 | Stevenage | 2 | 1 | Slight |
| Sun 10 Oct 1999 | Stevenage | 3 | 1 | Slight |
| Mon 11 Oct 1999 | Stevenage | 3 | 1 | Slight |
| Tue 12 Oct 1999 | East Hertfordshire | 2 | 1 | Slight |
| Tue 12 Oct 1999 | East Hertfordshire | 4 | 2 | Fatal |
| Mon 18 Oct 1999 | Stevenage | 3 | 2 | Serious |
| Thu 21 Oct 1999 | Stevenage | 2 | 1 | Slight |
| Sun 24 Oct 1999 | Stevenage | 2 | 1 | Slight |
| Wed 27 Oct 1999 | Stevenage | 2 | 1 | Slight |
| Wed 27 Oct 1999 | Stevenage | 2 | 4 | Slight |
| Wed 27 Oct 1999 | Stevenage | 2 | 4 | Slight |
| Thu 28 Oct 1999 | Stevenage | 2 | 2 | Slight |
| Sun 31 Oct 1999 | Stevenage | 3 | 1 | Slight |
| Sat 6 Nov 1999 | East Hertfordshire | 2 | 1 | Slight |
| Mon 8 Nov 1999 | North Hertfordshire | 2 | 1 | Slight |
| Tue 9 Nov 1999 | Stevenage | 2 | 2 | Slight |
| Fri 12 Nov 1999 | Stevenage | 2 | 1 | Slight |
| Tue 16 Nov 1999 | Stevenage | 1 | 3 | Slight |
| Fri 19 Nov 1999 | Stevenage | 2 | 1 | Slight |
| Sun 21 Nov 1999 | Stevenage | 2 | 2 | Serious |
| Sun 21 Nov 1999 | Stevenage | 2 | 2 | Serious |
| Tue 23 Nov 1999 | East Hertfordshire | 3 | 1 | Slight |
| Fri 26 Nov 1999 | Stevenage | 2 | 1 | Slight |
| Mon 29 Nov 1999 | Stevenage | 2 | 2 | Slight |
| Mon 29 Nov 1999 | Stevenage | 2 | 3 | Slight |
| Wed 1 Dec 1999 | Stevenage | 2 | 1 | Slight |
| Fri 3 Dec 1999 | East Hertfordshire | 1 | 1 | Slight |
| Sun 5 Dec 1999 | Stevenage | 2 | 1 | Slight |
| Mon 6 Dec 1999 | North Hertfordshire | 2 | 1 | Slight |
| Thu 9 Dec 1999 | Stevenage | 3 | 1 | Slight |
| Thu 9 Dec 1999 | Stevenage | 2 | 1 | Slight |
| Sat 11 Dec 1999 | East Hertfordshire | 2 | 1 | Slight |
| Mon 13 Dec 1999 | Stevenage | 2 | 1 | Serious |
| Thu 16 Dec 1999 | Stevenage | 2 | 1 | Slight |
| Fri 17 Dec 1999 | Stevenage | 2 | 1 | Slight |
| Fri 17 Dec 1999 | Stevenage | 2 | 1 | Slight |
| Sat 18 Dec 1999 | Stevenage | 2 | 1 | Slight |
| Sun 19 Dec 1999 | Stevenage | 2 | 2 | Slight |
| Wed 29 Dec 1999 | Stevenage | 2 | 2 | Slight |