The average retail price for a gallon of regular gas in the U.S. rose to $3.72 on Tuesday, but good luck trying to find gas below $4 a gallon in many parts of the country.

As gas prices have risen in 2012, it has not been an even increase across all regions.

Those in the center of the country continue to be supplied by refineries with access to cheaper, landlocked crude products, meaning that these areas have been relatively insulated from the increased prices seen in those areas near the coast that must pay prices set on the global market.

Pacific Coast states have seen an average increase of 54 cents per gallon since the start of the year, while prices in Mountain West states have increased by only 16 cents during the same period, according to the AAA Fuel Gauge Report.

In 12 California cities, the average price of gas has already topped $4.25. “California typically has higher gas prices due to the special blend of gas mandated by the state. This blend of gas burns more cleanly for pollution control,” said Jason Toews, a co-founder of GasBuddy.com.  ”Also, there was a refinery fire at a BP refinery in Washington state that has led to regional supply disruptions.”

The price of crude oil and upheaval in some parts of the world has also played a role in rising gas prices, according to analysts.  ”Any time you have uncertainly with Middle Eastern countries, speculators drive up the price of crude oil,” said Towes.  ”If war breaks out with Iran, that could cause gas prices to go even higher – even as high as $5 or $6 per gallon.”

With gas prices continuing to inch up, we asked Gasbuddy to compile a list of areas with the highest prices. The 15 areas with the highest gas prices are all in California.

Here’s a list of the 25 highest gas prices in the U.S.:

• Santa Barbara CA 4.350
• San Francisco CA 4.346
• Los Angeles CA 4.330
• San Diego CA 4.315
• Ventura CA 4.314
• Orange County CA 4.312
• Riverside CA 4.293
• San Jose CA 4.284
• San Bernardino CA 4.279
• Oakland CA 4.276
• Bakersfield CA 4.276
• Salinas CA 4.265
• Fresno CA 4.205
• Stockton CA 4.201
• Sacramento CA 4.200
• Honolulu HI 4.197
• Modesto CA 4.189
• Chico CA 4.181
• Anchorage AK 3.993
• New York City NY 3.993
• Long Island NY 3.988
• Medford OR 3.984
• Seattle WA 3.962
• Eugene OR 3.961
• Bridgeport CT 3.958

If your family or your business has been affected by this year’s rising gas prices, then you may want to consider purchasing a GPS fleet tracking system. A fleet GPS tracking system can provide an ROI in less than six months and immediately reduce fuel consumption.

In today’s tough economic climate, profit margins are slim and companies must implement as many cost-saving initiatives as possible. In order to stay competitive, companies have to look very closely at every penny spent. Utilizing a GPS fleet tracking system can be one of the most cost effective means to manage and reduce fuel consumption. A GPS fleet tracking system can help the average fleet reduce fuel costs by up to 20%.