Americans' travel plans for this Memorial Day weekend have gotten a lot more expensive as a result of President Donald Trump's war with Iran.A tracker released on Wednesday by the Institute on Taxation and Economic Policy (ITEP) projects that Americans will collectively spend an extra $3.5 billion on gas over the holiday weekend due to the global rise in oil costs.The costs of gas have risen sharply, to above $4.50 per gallon across the US on average, as a result of Iran's restriction of travel through the Strait of Hormuz in retaliation for the war that the US and Israel launched at the end of February.“Americans were already struggling with the high cost of living before this war started,” said Carl Davis, research director at ITEP. “The fact that their summer travel plans just got a whole lot more expensive isn’t going to help with that.”Using publicly available data and price forecasts from the US Energy Information Administration, the Federal Highway Administration, and the US Census Bureau, ITEP determined that as a result of the war, Americans have paid about $39.6 billion in additional gas costs in less than three months since the war began.It is projected that if current conditions continue, the total cost would be about $193 billion by the end of the year.The average household has already paid an additional $291 for gas since the war began and could spend $1,450 by year's end. However, the cost varies by region, and the tool allows users to estimate their household's added cost based on where they live and how many family members they have.The tracker only accounts for increased gasoline prices. It does not include price hikes caused by the war on other essentials, such as home utilities and food. Federal data released earlier this month showed that inflation has surged to its highest level since May 2023. It also does not account for the amount of taxpayer dollars spent on the war. Pentagon officials said that it had cost $25 billion in April, though other independent estimates have placed the total cost much higher.As Trump flails in response to rising prices, which have driven his approval ratings to their lowest low of his second term, he has proposed suspending federal gas taxes. Lawmakers in both parties have introduced bills that would temporarily suspend the tax, which adds an extra 18.4 cents per gallon of gasoline and 24.4 cents per gallon of diesel.However, ITEP argued that these proposals would be "ineffective as they offer very little relief to families" and that they "also run the risk of straining public budgets at a time when governments at all levels are facing some of the same higher costs as the public brought on by this war."