Trolley for the transport of a load, in particular on stairs, preferably of the self-propelled stairlift type, said trolley comprising: - a load-bearing frame on which at least two tracks are rotatably mounted so as to protrude from the lower part of said load-bearing frame, thus defining a lower sliding plane for the trolley, each of said tracks comprising a main portion and a secondary portion which is inclined / tiltable with respect to said main portion, said secondary portion being positioned at the front or rear of said trolley, said two tracks being spaced apart and each of said tracks being positioned at one side of said load-bearing frame, - motor or drive means of said two tracks, - a load structure which is configured to support the load to be transported, said load structure is articulated to said load-bearing frame in correspondence with an area (F, R) which is opposite to that (R, F) in which said secondary portion is provided, - means for varying the inclination between said load structure and the load-bearing frame, - supporting and sliding or rolling means which are mounted on said load structure, and being configured so as to assume: - a first condition in which said trolley is in contact with an underlying support surface with said support and sliding or rolling means while said tracks are spaced apart from said underlying support surface, and - a second condition in which said trolley is in contact with an underlying support surface with said tracks, while said support and sliding or rolling means are spaced apart from said underlying supporting surface and characterized in that said motor or drive means: - are independent for each of said two tracks, - are positioned internally between said two tracks in correspondence with said secondary portion of the tracks which is inclined with respect to said main portion, - they are aligned with each other along a direction corresponding, or parallel, to the direction of mutual spacing of the two tracks. - a load-bearing frame on which at least two tracks are rotatably mounted so as to protrude from the lower part of said load-bearing frame, thus defining a lower sliding plane for the trolley, each of said tracks comprising a main portion and a secondary portion which is inclined / tiltable with respect to said main portion, said secondary portion being positioned at the front or rear of said trolley, said two tracks being spaced apart and each of said tracks being positioned at one side of said load-bearing frame, - motor or drive means of said two tracks, - a load structure which is configured to support the load to be transported, said load structure is articulated to said load-bearing frame in correspondence with an area (F, R) which is opposite to that (R, F) in which said secondary portion is provided, - means for varying the inclination between said load structure and the load-bearing frame, - supporting and sliding or rolling means which are mounted on said load structure, - a first condition in which said trolley is in contact with an underlying support surface with said support and sliding or rolling means while said tracks are spaced apart from said underlying support surface, and - a second condition in which said trolley is in contact with an underlying support surface with said tracks, while said support and sliding or rolling means are spaced apart from said underlying supporting surface and characterized in that said motor or drive means: - are independent for each of said two tracks, - are positioned internally between said two tracks in correspondence with said secondary portion of the tracks which is inclined with respect to said main portion, - they are aligned with each other along a direction corresponding, or parallel, to the direction of mutual spacing of the two tracks.