A horizontal curve of radius $1080 \mathrm{~m}$ (with transition curves on either side) in a Broad Gauge railway track is designed and constructed for an equilibrium speed of $70 \mathrm{kmph}$. However, a few years after construction, the Railway Authorities decided to run express trains on this track. The maximum allowable cant deficiency is $10 \mathrm{~cm}$.
The maximum restricted speed (in $\mathrm{kmph}$ ) of the express trains running on this track is $\_\_\_\_\_\_\_$ (rounded off to the nearest integer).