Seeing a sudden jump in your car insurance premiums can be a gut-dropping moment. Car insurance can be expensive as it is, and sudden changes can be jarring both mentally and financially. To help you prepare for changes to your car insurance premiums, or even predict them, it is important to know what affects the cost of your car insurance. 
Marital Status
In most states, a change in your marital status can actually have a heavy affect on your car insurance premiums. If you get married, you may see a drop in your premiums. But if you get divorced, or if your spouse unfortunately passes away, you could see a rise in your car insurance rates. This may not seem fair, but it is all calculated through how much risk you present as a driver. Drivers going through recent emotional turmoil due to relationships are more likely to engage in bad driving habits and thus be involved in accidents.
A Drop in Your Credit Score
It is no secret that your credit score can change how much you pay for car insurance. If your credit score starts going down, you may see a rise in premiums. You can build your credit back up by paying off loans and debts, such as credit cards, and setting up automatic payments for all of your important bills so you never miss a payment.
Changes Around You
Sometimes, changes to your premiums are out of your control. You may see a change in your car insurance rates year by year depending on the changes around you. Upgrades and developments in your area, tax raises and other changes can all cause your car insurance rates you rise. Be sure to keep an eye on the developments in your community. If you notice a rise in crime rate, for example, you may expect to pay higher premiums in the coming year to compensate for the risk of theft or vandalism.
Car Accidents
Car accidents are one of the most obvious reasons for your car insurance to go up. If you get in an accident or file a claim, your insurance premiums are likely to rise in response. The rate at which they rise depends on the severity and frequency of an accident or claims. A single at-fault crash, for example, may raise your rates by around 30% while a DUI could cause your rates to skyrocket by 80%.
Not only does your own driving influence how much you pay, but those around you, as well. Say the main highway by your home is under heavy construction. Since the construction started, more car wrecks have occurred due to confusing lane changes, etc. You may see a rise in your premiums despite the fact that you drive defensively and avoid wrecks. This is because the rate of other crashes around you are anticipated through your car insurance policy. Even if you are a trusted driver, insurers try to compensate for potential losses in case someone else crashes into your vehicle and causes you to file a claim.