This would actually be a significant help to our family. I think it is an excellent idea. When is tax freedom day this year? Sometime in May? Time to start heading in the right direction.
The roads still need to be maintained. They aren't suggesting a spending cut, they are suggesting temporarily cutting the gas tax.
They'll end up either raising taxes elsewhere or borrowing to cover the costs.
At the same time, most of the "tax cut" will end up going to the oil companies as profits. Gasoline prices are set by supply and demand, and the oil companies can't magically create more refinery capacity.
When the taxes are removed, the price of gas will dip, but as soon as summer demand for gas hits, and demand starts outstripping supply, the price of oil is going to go up until demand drops back down to what they are able to supply.
This isn't going to result in significantly lower prices for consumers for long because the supply is capped. The price will be set based on demand, not based on them getting an extra 18.4 cents of what you pay at the pump.