Gadkari said in the Lok Sabha that his ministry has completed safety audit of 1.6 lakh bridges in the country and found more than 100 structures in dilapidated condition.
"100 bridges can be collapse anytime and they need immediate attention," he said during Question Hour.
He also referred to a tragedy where two state-run buses and some private vehicles were swept away after a British-era bridge over the Savitri river in the Konkan region of Maharashtra collapsed last year.
Referring to the delay in works on various road projects, the minister said this has been happening due to issues related to land acquisition, encroachment and environmental clearance.
He said road projects worth Rs 3.85 lakh crore were delayed due to various reasons in the past and most of these issues were resolved and their works are in progress.