Roads ACT spent $260,000 on emergency works to the Acton tunnel after a truck crashed into it last month.
The figure, provided to the ACT Insurance Authority, does not include the cost of future repairs.
It comes as the speed limit in the westbound tunnel looks set to remain at 60km/h for months to avoid vibrations.
An ACT government spokesman said on Friday that Roads ACT was assessing options for the repairs, after a truck carrying an excavator smashed more than 60 metres from the tunnel's ceiling, causing it to be closed for two days.
"Roads ACT will be making a decision on which option to adopt over the next few months," he said.
"Other ACT government directorates may consider making further claims in the future, but any amounts are unknown at this time."
Roads ACT director Tony Gill said this week the agency needed to decide how to repair the tunnel – including whether to reinstate the destroyed roof tiles, or remove all the tiles – before it returned the speed limit to 90km/h.
WorkSafe ACT was still investigating the crash, which occurred about 10.20am on October 20, and no penalties had been issued.
The driver had cleared the eastbound lanes of the tunnel earlier in the morning.
A spokesman for Charman Earthmoving and Heavy Haulage, who the driver works for, has said no special permit was required for the load.
Under National Heavy Vehicle Regulator requirements, trucks with a combined vehicle and load height exceeding 4.3 metres need a $70 over-height permit to travel on ACT roads. The westbound tunnel on Parkes Way is 4.9 metres high.
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