There are many career opportunities in railway train control, traffic management and communications throughout the world.
The range of activities is enormous, encompassing the latest software-based systems as well as "heritage" equipment. You might be interested in specification, design, installation, testing, maintenance, project engineering, research, product/system development ... the list is long. There is scope for people interested in electrical, electronic, mechanical and software engineering and information technology, as well as specialists in safety engineering, RAMS and human factors.
IRSE members typically, but not always, undertake a course or apprenticeship in electrical or electronic engineering, systems, software or safety engineering. Courses may be vocational, technical or academic in nature.
Your employer may sponsor you for a course, or to be an apprentice, or they may wish you to join their own engineering training scheme.
Specifically in the UK, you might like to look at the following websites: