Yes Becky, they are heavy and are meant to be. They held up fine running the mini excavator over them many times with no issue not to mention the rest of the the truck traffic. They are a great value. You can also use them as curb stops later to prevent your daughter from driving her Corolla into the back wall of the garage for the third time. The price is right, the service is great, just bring a strong young man to help you lift the box or open the box where is lays and remove them one at a time!