Is the word interseção the same in Brazilian and European Portuguese?

No

While the spelling of "interseção" is now identical in both Brazil and Portugal due to the Orthographic Agreement, there is a difference in typical usage. In Brazil, "interseção" is frequently used in everyday language to refer to road intersections or traffic junctions. In Portugal, "interseção" is viewed as a technical, mathematical, or highly formal term; in daily life, a Portuguese person will almost always use the word "cruzamento" to refer to a place where roads meet.

Brazilian Portuguese Usage

1. A interseção das duas ruas está interditada. (The intersection of the two streets is closed.)
2. O acidente aconteceu na interseção da avenida principal. (The accident happened at the intersection of the main avenue.)
3. Precisamos calcular a interseção desses dois conjuntos. (We need to calculate the intersection of these two sets.)
4. A interseção de culturas é o que faz esta cidade ser especial. (The intersection of cultures is what makes this city special.)
5. O sinal da interseção está com defeito. (The light at the intersection is broken.)

Continental Portuguese Usage

1. O acidente foi no cruzamento da avenida. (The accident was at the avenue crossing.)
2. O trânsito no cruzamento está muito lento. (The traffic at the crossing is very slow.)
3. A interseção de dois conjuntos matemáticos. (The intersection of two mathematical sets.)
4. Tenha cuidado ao passar por este cruzamento. (Be careful when passing through this crossing.)
5. O carro parou no cruzamento para dar passagem. (The car stopped at the crossing to give way.)