According to the New York State Department of Motor Vehicle's new driver brochure no matter what age you are, if you hold a learner permit, you may not drive:

• Unless accompanied by a supervising driver at least age 21 who has a license valid for operating the vehicle you are driving. For example, only a person with a motorcycle license may supervise a motorcycle learner.
• In a DMV road test area.
• On any street within a park in New York City, or any bridge or tunnel under the jurisdiction of the Triborough Bridge and Tunnel Authority.
• On the Cross County, Hutchinson River, Saw Mill River, or Taconic State parkways in Westchester County.

So even though you are 18 it does not appear that you can drive alone since you have only a NYS learner's permit. As you move up the graduated licensing system in New York you may be able to drive by yourself.

In New York the Department of Motor Vehicles notes that if you are age 18 or older when you pass your road test for a driver license, or obtain a license following revocation, you will be on probation for six months.

To find out more about the conditions of your New York learner's permit or what restrictions you will have on you as you pass through the graduated licensing system of NYS, contact the NYS DMV. To get cheap student car insurance quotes, follow this link.