The sign "Multi-lane vehicles allowed" (sign number 1024-20) indicates that the roadway ahead is designed for vehicles that occupy multiple lanes, or it allows for multi-lane traffic, typically indicating that vehicles with larger widths or lengths can proceed without restriction.

In practical terms, it means that drivers of multi-lane vehicles, such as buses, trucks, or vehicles towing trailers, are permitted to use the road. This sign may be used in areas where roads are designated to accommodate such vehicles, ensuring smooth traffic flow and safety.

It's important to always be aware of other vehicles and to follow any additional traffic regulations or signs that might be present in the area.