The plane with Ershad on board landed at Shahjalal International Airport around 4pm on Sunday after a five-day personal tour.
Dhaka Metropolitan Police Additional DC Rahima Akter Lucky said around 15,000 leaders and activists of the party stood on both sides of the road to welcome Ershad, who is also a special envoy to Prime Minister Sheikh Hasina.
But, the disorderly nature of the programme by Ershad's supporters blocked traffic on the road after 4pm.
"Their position slowed down vehicles," she said.
She also said the situation came to normalcy when Ershad left by a truck with other leaders of the party around 6pm.
"It took two and a half hours for me to reach Uttara from Banani," said Mahmud, a commuter.
The movement of the vehicle on the busy road was still slow after 6pm.
No leader of the party commented on the sufferings of people.