"Well trained, experienced staff" works for me. It may not have the intended play on words (if there is one, although I suspect they may have mixed up "trayecto" and "tracción").

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Note added at 32 mins (2015-01-19 19:42:21 GMT)
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Or maybe "Well grounded, highly trained staff..."

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Note added at 33 mins (2015-01-19 19:44:05 GMT)
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well–ground·ed adjective \-ˈgrau̇n-dəd\: having good training in a subject or activity

My understanding is that any railway company needs engineers (UK) or technicians to manage the traction control system of its trains

http://en.wikipedia.org/wiki/Railroad_engineer

It basically refers to the traction units staff. I´m sure about the meaning in Spanish, a bit less certain about the translation into English though. By “traction unit” I basically mean the locomotive, but not only, I also mean railway vehicles with a means of traction (tractive vehicles, see reference below). But I think in this case the locomotive staff is clearly meant by “personal de tracción”.


Definition of the term in Spanish:
http://www.trengranja.com/fgrplg1.pdf
FG - REGLAMENTO DE PERSONAL
Grupo 2: Personal de Tracción
n.iv - Jefe de Maquinistas
n.iii - Maquinista principal
n.iii - Maquinista
n.ii - Fogonero autorizado
n.ii - Ayudante autorizado
n.i - Fogonero-encendedor
n.i - Ayudante-preparador

http://www.gcrailway.co.uk/station-facilities/locomotive-she...
The coal store is outside the shed and staff rooms are provided for all grades of locomotive staff.

http://www.rne.eu/tl_files/RNE_Upload/Network Statements/RNE...
traction unit / tractive unit



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Note added at 1 hr (2015-01-19 20:30:58 GMT)
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For the UK, "staff" always in plural, of course.

personal de traccion is drivers