be, and often were, left unpainted except for the car's reporting marks that were required by law. By the end of the 1930s, railroads and car builders were debuting car body and interior styles that could only be dreamed of before. In 1937, the Pullman Company delivered the first cars equipped with roomettes—that is, the car's interior was sectioned off into compartments, much like the coaches that were still in widespread use across Europe. Pullman's roomettes, however, were designed with the single traveler in mind. The roomette featured a large picture window, a privacy door, a single fold-away bed, a sink and small toilet. The roomette's floor space was barely larger than the space taken up by the bed, but it allowed the traveler to ride in luxury compared to the multilevel semiprivate berths of old. Now that passenger cars were lighter, they were able to carry heavier loads, but the size of the average passenger load that rode in them didn't increase to match the cars' new capacities. The average passenger car couldn't get any wider or longer due to side clearances along the railroad lines, but they generally could get taller because they were still shorter than many freight cars and locomotives. As a result, the railroads soon began building and buying dome and bilevel cars to carry more passengers. 1950–present: High-technology advancements Carbody styles have generally remained consistent since the middle of the 20th century. While new car types have not made much of an impact, the existing car types have been further enhanced with new technology. Starting in the 1950s, the passenger travel market declined in North America, though there was growth in commuter rail. The higher clearances in North America enabled bi-level commuter coaches that could hold more passengers. These cars started to become common in the United States in the 1960s. While intercity passenger rail travel declined in the United States during the 1950s, ridership continued to increase in Europe during that time. With the increase came newer technology on existing and new equipment. The Spanish company Talgo began experimenting in the 1940s with technology that would enable the axles to steer into a curve, allowing the train to move around the curve at a higher speed. The steering axles evolved into mechanisms that would also tilt the passenger car as it entered a curve to counter the centrifugal force experienced by the train,