According to this source and several others (like Sylvester Turner, the mayor of Houston), a section of I-10 in West Houston called the Katy Freeway is the widest highway on Earth. Its widest point is when it intersects Beltway 8 with a total of 26 lanes.
However, some other sources dispute that claim. According to this article, there are many highways with more lanes than the Katy. For instance, there's a highway in Beijing with 50 lanes at a tolling point. I forgot where I read this, but another website says that Canada also has a freeway wider than I-10.
Is the Katy Freeway the widest highway in the world or not?