It is no wonder Network Rail are trying to reduce the number of unmanned level crossings, particularly those used intermittently by farm traffic.  The vast majority have a maximum approach speed (for the train) of 60 mph together with an instruction to whistle.  Between Haughley Junction and Diss there are so many that the line speed becomes 60 by default.
Much more serious however are the knock-on effects of an incident at one of these crossings.  In early June a car driver decided to dodge around the automatic half barriers at Trimley.  The car was struck at 11.10 in the morning by the GBRf (Great British Rail freight) service between Hams Hall (Birmingham) and Felixstowe.

The freight train came to a standstill some distance down the track, British Transport Police investigated the incident and arrested the car driver.  They were able to hand the line back to Network Rail for safety checks less than two hours later.  However it was not until 16.15 that the freight train could be moved (a replacement engine driver was required) and after 17.00 when the line reopened.

The knock-on effect was that the follow-on freight services were held, on the East Suffolk line between Ipswich and Westerfield, and on the East Coast Main Line between Haughley Junction and Ipswich, and between Colchester and Ipswich.

This curtailed the movement of passenger services, trains were delayed and in the wrong place for return journeys.  All services to Felixstowe were cancelled for the rest of the weekend, and for those passengers on Peterborough Station, a long, long wait without explanation.  

The saving grace, if there was one is that the incident took place on a Saturday. Had it been a weekday commuters would have, yet again, been stranded at Liverpool Street into the evening.