The Circuit de Barcelona-Catalunya announced it had been sold out for the 2022 edition of the race after going through two COVID-19 years with limited attendance, stating 300,000 flocked to the Barcelona venue across the weekend.
But soon enough it became apparent the venue was not prepared for the sell-out crowd, with larges queues forming around the limited food and drinks concessions and toilets.
Particularly on Saturday and Sunday, the severe congestion on the access roads around the circuit ground traffic to a halt, with fans then struggling to find parking space. The small Montmelo train station also struggled to transport fans to and from the city centre during peak hours.
The crowd problems were made worse by the heat, with Catalonia experiencing its hottest week of the year so far as temperatures soared above 35 degrees on the weekend, leaving many fans to brave the weather without adequate provisions.
Many fans voiced their displeasure on social media, with some even suggesting they wouldn't return for race day despite having bought a ticket.
Hours after the race F1 released a statement calling the congestion issues "not acceptable", urging the organisers to put a plan in place to avoid a similar meltdown next year.
"The huge number of fans at this event both inside and outside the circuit created the traffic issues for the fans," an F1 statement said.
"We have made the promoter aware that this is not acceptable and must be fixed for next season."
Several parts of the Montmelo circuit had been renovated for this year, but some of its key spectator facilities have remained virtually untouched over the years.
As the site of Max Verstappen's first-ever Formula 1 win and a popular tourist destination, the Spanish GP has seen a surge of Dutch fans travelling to Catalonia in recent years.
Carlos Sainz's improved results with Ferrari and Fernando Alonso's comeback have also seen local fans find their way back to the venue, which has been hosting F1 races since its inception in 1991.