Railway track Besides the rail change, the fastening is also replaced on the entire line, resulting in a uniform superstructure, with regular maintenance the M3 metro superstructure will be completed for at least 30 years, in addition to the planned maintenance. With this solution, it is possible to modify the rail support distance — the safe calculation of the axle load and a more favourable support distance of about 70-75 cm and the introduction of a uniform fastening system. Thanks to the compression of the attachments (~ 75 cm), the rails are more resistant to dynamic stresses. In addition to modifying the support distances, the new fastening system also allows long-term wear of track usage and environmental considerations (noise and vibration). The body of the extension may also be adapted to the uniform superstructure. Signalling and AVR systems still functionally meet traffic and technological needs, therefore, a scheduled replacement of mechanical components (e.g. stops, gearboxes) and refurbishment of track circuits, beacons and AVR equipment is essential to ensure proper operational safety for a further 20-25 years. It is also necessary to renovate interior equipment: D-67 interlock and power supply system, local domino control panels, all six treatment zones. The on-board equipment of the AVR will be relocated to the refurbished vehicles. Stations, interior installation The project involves the extended renovation of the stations and surface buildings. The refurbishment of the operating spaces is carried out in accordance with the new requirements and regulations, with the new premises required in connection with the technological, technical equipment or operator’s needs. Full accessibility has been discarded due to very high investment costs, longer construction times and higher construction risks. The accessibility of the entire transport system is achieved through surface transport. The subject of the intervention is the power supply of the metro line, by which we mean the system from the 10 kV connection point of the ELMŰ receiving equipment to the end of the cables connected to the rails of the 825 V system, as well as the protection and monitoring systems within the station serving it. The 10 kV and 825V DC equipment will be completely replaced, as opposed to retrofit refurbishment. Rail Telecommunications Developments affect line and station systems, including the refurbishment, replacement of communications equipment and the establishment of service stations. New integrated rail telecommunications systems will be installed. One part of the telecommunication equipment to be installed serves the comfort and safety of passengers (voice and visual passenger information, emergency telephones, platform infrara), while the other part allows operation (dispatch and other telephone systems, operating tables). For the cooperation of the above systems, the establishment of an optical data transmission system is essential, and the establishment of a full range of fire alarm and extinguishing control systems is a basic requirement during the renovation. Development of the vehicle plant The development of the vehicle site focuses on the maintenance of the plant, does not include any interventions that significantly reduce costs or environmental impacts. Technical content: removal of roofings, completion of construction, engineering and electrical works strictly necessary in buildings, changes in fire protection required by the authorities, adaptations necessary for technological change, and minimal environmental protection investments.