What are the Octroi Charges or Taxes ? Why does one have to pay them when u transport ur motorcycle on a train from one place to another ? I have heard of these charges only in the metro cities.

Ive also heard that the tax is refundable and also that its charged because your importing a vehicle to the metro city such as mumbai.

Why dont they charge you when you ride your bike to mumbai ?

Why are these taxes present ? Please clear my queries... Been puzzled about this for quite a while. Tried my best by googling these but was left with no clear answer.