Monthly SPAD/TPWS Update
June 2014
Issued by Alexander Moor, Safety Intelligence Analyst, RSSB
Key statistics
All SPADs annual moving
total (AMT)
310
↑
Last month: 302
Last year: 266
20+ SPADs annual
moving total
89
17
↓
Last month: 92
Last year: 73
Multi-SPAD signals (two or
more SPADs in five years)
125
16+ SPADs annual
moving total
↑
Last month: 123
Last year: 124
↑
Last month: 15
Last year: 13
Annual moving percentage
of TPWS brake demands
SPAD risk relative to
September 2006
54% ↑
74% ↑
Last month: 52%
Last year: 59%
Last month: 67%
Last year: 58%
There were 32 SPADs during June. This is 8 greater than in June 2013. The three-year average for the
previous three June's is 23.7.
The annual moving total, which was 266 a year ago, is now 310; 8 greater than last month. An increase of
44 since last year.
Of the 32 SPADs during June: 11 involved TPWS brake demands; 8 were interventions and 3 were
activations.
Monthly performance
SPAD Numbers
33
24 25
26
30
28
22
SPAD Risk
32
32
22
17
19
400
140%
350
120%
300
100%
250
150
J A S O N D J F M A M J
74%
200
80%
60%
100%
100
40%
50
20%
0
Sep-06
0%
Sep-08
Sep-10
Sep-12
5 of June’s SPADs were risk ranked 16+; of which 2 were risk ranked 20+. There are currently 5 SPAD Risk
Rankings outstanding for June.
The blue line in the chart above right shows the trend in underlying SPAD risk since the Sept 2006
benchmark date. At the end of June, the underlying level of SPAD risk was estimated to be 74% of the
This update regarding SPAD and TPWS performance for June 2014 is based on data available as at the date
of issue and is subject to change as further information becomes known.
The AMT refers to SPADs which have occurred in the last 12 months of the relevant period. Last month and last year are what the
respective measure was at those points.
A TPWS intervention occurs when TPWS applies the brakes before, or in the absence of, the driver doing so.
A TPWS activation occurs when a driver has already applied the brakes before the TPWS operates.