General Brazilian
estrada de trânsito lento; pista congestionada
Most common usage in Brazilian Portuguese
Rio de Janeiro
estrada travada; via lenta
Colloquial term 'travada' often used for congested roads
São Paulo
rodovia congestionada; via lenta
Common in traffic reports and news
Portugal
estrada congestionada; via de trânsito lento
Formal register preferred in European Portuguese