You can claim travelling expenses if your employer issues you a T2200 - Declarations of Conditions of Employment form and states that you must pay for these expenses yourself. If they reimburse you they must include that amount on your T4 as taxable earnings. Travelling expenses include food, beverage, lodging and transportation (such as airplane, train, bus, etc) expenses but not motor vehicle expenses.

In order to claim motor vehicle expenses, you must be normally required to work away from your employer's place of business or in different places. Four trips per year would not qualify you for a motor vehicle expense claim. 

Here's a link to the CRA's guide to Employment Expenses: https://bit.ly/2Tt9PWZ