This document must be read in conjunction with the Guideline 01: The Main Document, which addresses all definitions and standards used in the set of guiding documents.

• The evidence applies to all new or planned railway lines or those under construction and other guided transport systems in the Kingdom of Saudi Arabia that hold or seek to obtain a railway safety certificate and an operating license.

• To achieve and ensure the safe design and construction on various organizations in the design and construction of railway projects, they must understand their roles and responsibilities, as well as the main coordination and arrangements for that. In this regard, this will include the concerned organizations such as the developer, designer, contractor, and the Transport General Authority.

• It is a public or private entity and is usually the owner/funder of the future transportation infrastructure.

• For the purposes of this evidence, the developer or client is the entity responsible for promoting, announcing, and funding the project, as well as defining the scope and outputs of the project. The developer's responsibility is to prepare the specifications and oversee the progress of the project activities. They ensure through appropriate management and supervision that the project has been executed according to the specifications.

• The developer must also ensure that the railways comply with the laws and regulations of the Kingdom of Saudi Arabia, as well as the best international standards and practices, while determining the level of quality and independent assurance required based on the complexity of the project.

The designer is required to take all reasonable steps to provide the necessary information required for the design and related to the design of the project, its construction, maintenance, and operation, and to appropriately assist the developer, other designers, and contractors in complying with their responsibilities related to safety and duties.

• It is the entity that the developer contracts with to design and/or build or operate the transport system.

• The contractor shall be responsible for determining the construction phase, which should detail the safety organization and the arrangements necessary to ensure the verification of the safety and integrity of the design. They must also develop a Safety Assurance Plan (SAP) and confirm it in accordance with international standards EN 50126, EN 50128, and EN 50129. The contractor or the main contractor in any consortium shall be legally responsible just like the service provider, as specified in standard EN 50126. The authority requires the contractor to appoint an independent specialized consultant (ICP) accredited by the authority.