You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Newcastle_upon_Tyne

Context:
The system is currently undergoing a period of refurbishment and modernization, entitled 'Metro: All Change.' The programme has replaced all ticket machines and introduced ticket gates at the busiest stations - part of the transition to smart ticketing. All Metro trains are being completely refurbished and most stations are undergoing improvement works (or in some cases complete reconstruction, for example North Shields). In addition; tracks, signalling and overhead wires are also being overhauled. Longer term plans include the procurement of an entirely new fleet of trains and further extensions to the system. Proposed routes include to Newcastle's west end, to the Cobalt business park in North Tyneside, to the Metrocentre in Gateshead and to additional locations in Gateshead, South Tyneside and Sunderland. Several of the proposed routes would require trams as opposed to the current light rail trains.

Question:
What does the replacement of the ticket machines and introduction of ticket gates herald the transition to?

smart ticketing