Many readers have been in touch seeking clarification of the visa situation regarding criminal records. This is the exact advice on the website of the US Embassy in London:
‘Travelers with minor traffic offenses which did not result in an arrest and/or conviction for the offense may travel visa free, provided they are otherwise qualified. If you are not sure whether or not you are eligible to travel visa free, the only way to resolve this question would be to apply for a visa.
If the traffic offense occurred while you were in the United States, and you have an outstanding fine against you or you did not attend your court hearing, it is possible there may be a warrant out for your arrest, and you will experience problems when applying for admission into the U.S. Therefore you should resolve the issue before traveling by contacting the court where you were to appear. If you do not know the address of the court then information is available from the Internet at www.uscourts.gov/links.html.
Travelers who have been arrested, even if the arrest did not result in a criminal conviction, and those with criminal records, (the Rehabilitation of Offenders Act does not apply to U.S. visa law), are required to apply for visas. If they attempt to travel without a visa, they may be refused entry into the United States. Please follow this link for further information.
People have asked me: how do US immigration authorities know that you may have an old conviction – does the Home Office share its criminal record information with the US? The Home Office says it shares only information regarding people deemed to be a security risk.
However, the problem is: if you decide not to declare your criminal conviction and it is subsequently discovered by the US authorities, you may be deported and subsequently prevented from entering the country again. It’s not a risk worth taking.