A method of controlling access to a reserve zone via a system for controlling access to the reserve zone, the method comprising the following steps: - presenting a mobile terminal to an access control point of the access control system, - capturing an image carried by the access control point, representative of an encoded item of computer data, using a camera of the mobile terminal, and - decrypting, via the mobile terminal, the image captured by the camera, to deduce the encoded computer data therefrom, the encoded item of computer data being a unique identifier of the access control point, and the method further comprising the following steps: - establishing a wireless connection between the mobile terminal and the access control point, by the mobile terminal, using the unique identifier of the decrypted access control point, - sending to the access control point, via the mobile terminal, an access entitlement to the reserve zone stored in its memory, via a wireless connection, the access entitlement comprising an expiration timestamp and a transportation contract, - first check of the validity of the data of said access entitlement by the access control point, said check comprising the following substeps: ∘ reading the expiration timestamp of the access entitlement, and ∘ comparing said expiration timestamp with the date-time of the presentation moment of the mobile terminal to the access control point, - second check (140, 330) of the validity of the data of the access entitlement, and - if it is concluded that said data of the access entitlement is valid as part of the second check (140, 330), replacing (150, 335) the expiration timestamp of the access entitlement with a later expiration date-time. - presenting a mobile terminal to an access control point of the access control system, - capturing an image carried by the access control point, representative of an encoded item of computer data, using a camera of the mobile terminal, and - decrypting, via the mobile terminal, the image captured by the camera, to deduce the encoded computer data therefrom, - establishing a wireless connection between the mobile terminal and the access control point, by the mobile terminal, using the unique identifier of the decrypted access control point, - sending to the access control point, via the mobile terminal, an access entitlement to the reserve zone stored in its memory, via a wireless connection, the access entitlement comprising an expiration timestamp and a transportation contract, - first check of the validity of the data of said access entitlement by the access control point, said check comprising the following substeps: ∘ reading the expiration timestamp of the access entitlement, and ∘ comparing said expiration timestamp with the date-time of the presentation moment of the mobile terminal to the access control point, ∘ reading the expiration timestamp of the access entitlement, and ∘ comparing said expiration timestamp with the date-time of the presentation moment of the mobile terminal to the access control point, - second check (140, 330) of the validity of the data of the access entitlement, and - if it is concluded that said data of the access entitlement is valid as part of the second check (140, 330), replacing (150, 335) the expiration timestamp of the access entitlement with a later expiration date-time.