Roller coaster provided with one or more roller coaster seat assemblies adapted to carry one or more passengers, wherein each seat assembly comprises: (a) a seat, capable of accommodating a passenger, comprising a seating surface,a back support with a back support surface and a headrest; (b) a pivot axis extending behind the headrest at a distance above the seating surface which pivot axis is substantially parallel to the back support and substantially parallel to the seating surface; (c) a bar construction comprising a hip bar and one or more pivot arms formed integral with the hip bar, which bar construction is pivotable about the pivot axis from a raised position in which the hip bar is raised from the seating surface to allow a passenger to sit down in the roller coaster seat assembly, to a lowered position, in which • the hip bar is in the vicinity of the seating surface, so as to extend over the lap and in front of the hips of a passenger, (d) a belt construction connected to the back support and to the bar construction comprising at least two shoulder straps, further being provided with an adjustable length mechanism to allow for adaptation to the passenger in the lowered position of the bar construction such that the shoulder straps extend across the shoulders and upper part of the body of a passenger seated in the roller coaster, characterized in that in the lowered position of the bar construction at least part of the pivot arm which is at the level of the upper body part and the head of the person seated in the seat assembly is located behind an imaginary plane that extends tangent and substantially parallel with the back support surface, such that the pivot arm can easily pass the passenger and the back support when lowering or raising the bar construction, such that the bar construction does not take away the view of the passenger and does not limit the movements of the arms of the passenger. (a) a seat, capable of accommodating a passenger, comprising a seating surface,a back support with a back support surface and a headrest; (b) a pivot axis extending behind the headrest at a distance above the seating surface which pivot axis is substantially parallel to the back support and substantially parallel to the seating surface; (c) a bar construction comprising a hip bar and one or more pivot arms formed integral with the hip bar, which bar construction is pivotable about the pivot axis from a raised position in which the hip bar is raised from the seating surface to allow a passenger to sit down in the roller coaster seat assembly, to a lowered position, in which • the hip bar is in the vicinity of the seating surface, so as to extend over the lap and in front of the hips of a passenger, • the hip bar is in the vicinity of the seating surface, so as to extend over the lap and in front of the hips of a passenger, (d) a belt construction connected to the back support and to the bar construction comprising at least two shoulder straps, further being provided with an adjustable length mechanism to allow for adaptation to the passenger in the lowered position of the bar construction such that the shoulder straps extend across the shoulders and upper part of the body of a passenger seated in the roller coaster, characterized in that in the lowered position of the bar construction at least part of the pivot arm which is at the level of the upper body part and the head of the person seated in the seat assembly is located behind an imaginary plane that extends tangent and substantially parallel with the back support surface, such that the pivot arm can easily pass the passenger and the back support when lowering or raising the bar construction, such that the bar construction does not take away the view of the passenger and does not limit the movements of the arms of the passenger.