The first minister still intends to decide whether to build the M4 relief road before standing down, he has said.
Some Labour AMs want Carwyn Jones's successor, who will be appointed in December, to take the decision.
But Mr Jones said he expected to have the information he needs to make up his mind by the end of the month.
Civil servants are going through the unpublished findings of a public inquiry into the Welsh Government proposals.
The preferred option is to build nearly 15 miles of motorway to the south of Newport - known as the black route - but a final decision has not yet been taken.
AMs have been promised a vote on the project. It was expected to happen in the Senedd on 4 December - two days before Welsh Labour announces the result of its leadership election.
Mr Jones will hand over the reigns as first minister to his successor the following week.
However ministers are yet to schedule the vote.
Asked by BBC Wales whether he still intended to decide whether the road is built, Mr Jones said: "Yes, the plan is that I will take the decision.
"I'll tell you where we are - the inspector's report has been received. It's more than 500 pages long so it takes some time to digest and analyse legally.
"I've not seen the report yet, but I expect that the report will be ready for me to take a decision by the end of the month."