Fatal
Serious
Slight
Uncategorised
| Date | Local Authority | Vehicles | Casualties | Severity |
|---|---|---|---|---|
| Thu 1 Jan 1998 | Cardiff | 1 | 1 | Serious |
| Fri 9 Jan 1998 | Caerphilly | 1 | 1 | Slight |
| Fri 9 Jan 1998 | Caerphilly | 1 | 1 | Serious |
| Wed 14 Jan 1998 | Telford and Wrekin | 1 | 1 | Slight |
| Fri 16 Jan 1998 | Caerphilly | 2 | 1 | Slight |
| Sat 17 Jan 1998 | Caerphilly | 1 | 1 | Slight |
| Wed 21 Jan 1998 | Caerphilly | 1 | 1 | Slight |
| Fri 23 Jan 1998 | Caerphilly | 2 | 2 | Slight |
| Thu 29 Jan 1998 | Caerphilly | 2 | 2 | Slight |
| Wed 4 Feb 1998 | Cardiff | 2 | 1 | Slight |
| Wed 4 Feb 1998 | Caerphilly | 1 | 1 | Slight |
| Fri 13 Feb 1998 | Caerphilly | 2 | 2 | Slight |
| Sat 14 Feb 1998 | Caerphilly | 2 | 1 | Slight |
| Thu 26 Feb 1998 | Caerphilly | 1 | 1 | Slight |
| Sat 28 Feb 1998 | Cardiff | 2 | 1 | Slight |
| Tue 3 Mar 1998 | Caerphilly | 1 | 1 | Slight |
| Fri 6 Mar 1998 | Cardiff | 1 | 1 | Serious |
| Fri 6 Mar 1998 | Cardiff | 1 | 3 | Serious |
| Sun 8 Mar 1998 | Caerphilly | 1 | 1 | Slight |
| Fri 13 Mar 1998 | Caerphilly | 1 | 1 | Slight |
| Wed 18 Mar 1998 | Caerphilly | 1 | 1 | Slight |
| Wed 18 Mar 1998 | Caerphilly | 2 | 1 | Slight |
| Thu 19 Mar 1998 | Caerphilly | 2 | 2 | Slight |
| Thu 2 Apr 1998 | Caerphilly | 2 | 4 | Slight |
| Thu 2 Apr 1998 | Cardiff | 2 | 1 | Slight |
| Fri 3 Apr 1998 | Cardiff | 2 | 2 | Slight |
| Sat 4 Apr 1998 | Caerphilly | 1 | 1 | Slight |
| Tue 7 Apr 1998 | Cardiff | 2 | 1 | Slight |
| Wed 8 Apr 1998 | Caerphilly | 1 | 1 | Slight |
| Wed 8 Apr 1998 | Caerphilly | 3 | 1 | Slight |
| Thu 9 Apr 1998 | Caerphilly | 2 | 1 | Slight |
| Sun 3 May 1998 | Cardiff | 2 | 1 | Serious |
| Sun 10 May 1998 | Caerphilly | 2 | 3 | Slight |
| Mon 11 May 1998 | Caerphilly | 1 | 1 | Slight |
| Wed 20 May 1998 | Caerphilly | 2 | 1 | Slight |
| Sun 24 May 1998 | Cardiff | 2 | 1 | Slight |
| Thu 28 May 1998 | Caerphilly | 1 | 2 | Serious |
| Sat 30 May 1998 | Cardiff | 1 | 2 | Slight |
| Sat 30 May 1998 | Cardiff | 2 | 3 | Slight |
| Sun 31 May 1998 | Caerphilly | 2 | 3 | Serious |
| Sun 21 Jun 1998 | Caerphilly | 2 | 2 | Slight |
| Thu 25 Jun 1998 | Caerphilly | 3 | 3 | Slight |
| Fri 10 Jul 1998 | Caerphilly | 2 | 1 | Slight |
| Fri 17 Jul 1998 | Cardiff | 2 | 1 | Slight |
| Sat 18 Jul 1998 | Caerphilly | 2 | 2 | Slight |
| Sat 18 Jul 1998 | Caerphilly | 1 | 1 | Serious |
| Mon 27 Jul 1998 | Cardiff | 2 | 2 | Slight |
| Mon 3 Aug 1998 | Cardiff | 1 | 1 | Slight |
| Sun 16 Aug 1998 | Cardiff | 2 | 1 | Slight |
| Tue 18 Aug 1998 | Caerphilly | 2 | 1 | Slight |
| Mon 24 Aug 1998 | Cardiff | 2 | 1 | Slight |
| Wed 26 Aug 1998 | Cardiff | 2 | 1 | Slight |
| Fri 28 Aug 1998 | Caerphilly | 2 | 1 | Slight |
| Fri 18 Sep 1998 | Cardiff | 2 | 1 | Slight |
| Wed 23 Sep 1998 | Caerphilly | 2 | 2 | Slight |
| Mon 28 Sep 1998 | Caerphilly | 3 | 4 | Slight |
| Mon 28 Sep 1998 | Caerphilly | 1 | 1 | Serious |
| Mon 28 Sep 1998 | Cardiff | 4 | 1 | Slight |
| Fri 2 Oct 1998 | Caerphilly | 3 | 1 | Slight |
| Sun 11 Oct 1998 | Caerphilly | 2 | 1 | Slight |
| Mon 12 Oct 1998 | Caerphilly | 2 | 1 | Slight |
| Fri 16 Oct 1998 | Caerphilly | 1 | 1 | Slight |
| Sun 18 Oct 1998 | Caerphilly | 2 | 1 | Slight |
| Sun 18 Oct 1998 | Cardiff | 1 | 1 | Fatal |
| Tue 20 Oct 1998 | Cardiff | 2 | 2 | Slight |
| Fri 23 Oct 1998 | Caerphilly | 1 | 1 | Slight |
| Fri 23 Oct 1998 | Cardiff | 3 | 2 | Slight |
| Thu 29 Oct 1998 | Caerphilly | 1 | 1 | Slight |
| Sun 15 Nov 1998 | Caerphilly | 1 | 1 | Slight |
| Wed 18 Nov 1998 | Caerphilly | 1 | 1 | Slight |
| Fri 20 Nov 1998 | Caerphilly | 1 | 1 | Slight |
| Tue 1 Dec 1998 | Caerphilly | 2 | 1 | Slight |
| Tue 8 Dec 1998 | Caerphilly | 2 | 1 | Slight |
| Thu 10 Dec 1998 | Caerphilly | 3 | 1 | Slight |
| Sun 20 Dec 1998 | Caerphilly | 1 | 2 | Slight |
| Wed 23 Dec 1998 | Caerphilly | 2 | 1 | Slight |
| Fri 25 Dec 1998 | Cardiff | 1 | 2 | Serious |