Prompted by the growing interest in intermediate forms of public transport, and with investment from The National Endowment for Science, Technology and the Arts (NESTA), TDI has developed a new form of electronic guidance.  Called ‘Safeguide’, the system majors on simplicity and above all safety. 

Based around the concept of detecting low frequency signals generated through underground cables, the breakthrough with Safeguide is its unique, high integrity watchdog steering system.  This patented device is designed to automatically take over from the primary system should an emergency condition be detected.  Such an approach differs significantly from previous forms of electronic guidance, which have relied on the driver to take evasive action in the event of failure.  To ensure the highest possible level of safety integrity, TDI has designed the watchdog system against very specific performance criteria identified in a safety case strategy.  This strategy has been developed over the past two years through painstaking consultation with industry experts and Her Majesty's Railway Inspectorate (HMRI).

Equipped with Safeguide, the zero emission Minitram, which is also double ended like a conventional tram, will be unique in its approach to certification.  In every application, it will be approved for use as a PSV by the Vehicle Inspectorate as well as an ultra-light tram (carrying a full safety case) under HMRI regulations.  The Minitram system is currently being considered for use in park-and-ride and intermodal feeder type applications in environmentally sensitive areas both in the UK and overseas.

Aside from the obvious benefits of a fixed infrastructure transit system, the four-wheel steered Minitram, under Safeguide control, can improve on the performance of conventionally guided vehicles by achieving a virtually gapless, level boarding solution.  This is of particular interest to operators and local authorities now faced with very stringent access requirements under DDA legislation.  In conjunction with Type 3 Minitrams, the guidance system can also ensure precise steering along narrow transit corridors.  This is especially relevant in historic town centres where conventional bus lanes or tram lines would be impractical.

TDI believes that Safeguide offers significant advantages over other forms of guidance such as O’bahn (kerb guidance).  For example: the infrastructure is more or less invisible; it is inexpensive to install (a complete Minitram system inclusive of vehicles and infrastructure is reckoned to cost around £1m per km); it will work in all weather conditions and there are no trip hazards for pedestrians.