Sir, I agree with Sri Kasturi Sir's view. Service means any activity carried out by one person for another for consideration. And consideration means any amount that is charged for service provided or agreed to be provided by service provider to service receiver.
In your query, GTA is paid for carrying goods from one place to another. The consideration is agreed for doing the same. Toll is not the charges for the service provided, but in fact it is incidental charges. The service provider has to pay toll while his vehicle is on road. And this is claimed from service receiver. Hence it is reimbursement and not consideration and therefore no service tax on toll.
However, w.e.f. 14.05.2015, reimbursable expenses are also considered as consideration and service tax shall be paid. But still there is logical to think that toll expenses claim is supported with receipt. Thanks.