Both crashes would have been prevented by an operational automatic train protection (ATP) system, wider fitting of which had been rejected on cost grounds.

The crash severely damaged public confidence in the management and regulation of safety of Britain's privatised railway system.

Since both the Paddington and Southall crashes had reopened public debate on ATP, a separate joint inquiry considering the issue in the light of both crashes was also held in 2000; it confirmed the rejection of ATP and the mandatory adoption of a cheaper and less effective system, but noted a mismatch between public opinion and cost-benefit analysis.

At about 8:09, as it was entering the Up Line, it collided nearly head-on and at a combined speed of approximately 130 mph (210 km/h) with the 06:03 First Great Western train from Cheltenham to Paddington.

The diesel fuel it was carrying was dispersed by the collision and ignited, leading to a series of fires in the wreckage, particularly in coach H near the front of the HST, which was completely burnt out.

[4] His driver training was found to be defective on at least two grounds: assessing situation-handling skills, and being notified of recent local incidents of Signals Passed at Danger (SPAD).

[7] Furthermore, 5 October 1999 was a clear day and at just past 08:00 the sun would have been low, behind Hodder, meaning that sunlight would reflect off yellow aspects, reducing visibility.

[30] Between February 1998 and the accident there had been four separate groups set up with the aim of reducing SPADs; their existence, membership and functions overlapped.

[38] Hodder had only qualified 13 days earlier; he was ex-navy with no previous experience as a railway worker, but no special attention was paid to this in either training or testing.

[41] After a previous SPAD, Thames Trains had commissioned a cost–benefit analysis (CBA) study specific to the Paddington situation which came to the same conclusion.

[45] Flank protection would have increased the 'overlap' (the distance for which a train could run past the signal before fouling lines) at SN109; the desirability of doing so should have been considered by the risk assessment which had not taken place.

Their understanding of the instructions was that they should wait to see if the driver stopped of his own accord before attempting to contact him; this interpretation was supported by their immediate manager.

[49] The general picture which emerged was of a slack and complacent regime, which was not alive to the potentially dire consequences of a SPAD or of the way in which signallers could take action to deal with such situations.

She attributed these deficiencies to three causes: A fortnight before the crash the HSE had announced an intention to require the adoption of TPWS (an upgrade of AWS, which could stop trains travelling at less than 70 mph within the overlap distance of a red signal delivering it assessed about 2⁄3 the safety benefits of ATP at much lower cost) by 2004 (advanced, a week after the crash, to 2003[53]).

In the year between Ladbroke Grove and the joint inquiry the rail industry (if not the general public) had become largely committed to the adoption of TPWS.

Both TPWS and ETCS would be mandatory and therefore their cost implications need not be considered by any body other than the UK government and the EU Commission.

Since it also had commercial interests in these issues TOCs were unhappy with this:[60] Cullen recommended that safety case acceptance should be directly by HSE in future, and a new body should be set up to manage Railway Group Standards.

[61] In 1996 ScotRail had initiated the creation of a confidential rail safety reporting system (later to become CIRAS) formed from an independent panel chiefly from Strathclyde University.

[62] CIRAS now provides services to all rail workers and operating sectors throughout England, Scotland, Wales and the Republic of Ireland (ROI).

On 5 April 2004, Thames Trains was fined a record £2 million after admitting violations of health and safety law in connection with the crash and ordered to pay £75,000 in legal costs.

[68] On 31 October 2006, Network Rail (the successor body to Railtrack, formed in the wake of a subsequent train crash at Hatfield) pleaded guilty to charges under the Health and Safety at Work Act 1974 in relation to the accident.

In a subsequent case arising out of a manslaughter committed by one of the victims of the crash, Kerrie Gray, who experienced post-traumatic stress disorder and went on to kill a pedestrian, legal issues were raised regarding the legal principle known as ex turpi causa non oritur actio, which holds that illegal actions cannot form a basis for damages claims.

Mr Gray was found guilty of the offence of manslaughter by reason of diminished responsibility, and detained in psychiatric care as a result.

[72][73]Pam Warren wrote the book From Behind the Mask which narrates her experiences during the crash, her recovery, and how it has affected her life and relationships.