The Minnesota Department of Transportation is running low on MnPASS transponder clips, so starting Thursday the agency will stop accepting requests for new accounts.

A MnDOT spokeswoman told the Drive that signups would resume in late March or early April when a new shipment is expected to arrive.

The clips are a key part of the transponder. They activate the transponder and allow readers to deduct the tolls that solo drivers pay to use the HOT lanes on I-394 and I-35W that are otherwise reserved for buses, motorcycles and carpools.

MnDOT was unable to get its most recent shipment from the lone overseas vendor because of a "glitch" in purchasing and shipping, said spokeswoman Bobbie Dahlke. Current MnPASS holders received an email Wednesday notifying them of the problem.

With about 500 new customers signing up each month, the agency was on pace to run out of clips. The agency needs to keep clips on hand for existing customers to replace those that break or need to be replaced for other reasons. To manage the remaining inventory until new clips arrive, MnDOT decided to curtail new signups.

The agency said new customers can request to get an email when signups for new accounts resume by going to www.mnpass.org.

Currently MnDOT services about 25,000 accounts and 32,000 transponders as some account holders have more than one.

Although transponder holders can use any HOT lane in the metro area, the latest numbers indicate that 14,000 account holders use the HOT lane on I-394 between downtown Minneapolis and Minnetonka. Another 11,000 account holders use the HOT lane on I-35W between downtown Minneapolis and Burnsville.

Signups for the new I-35E MnPASS lane opening later this year won't begin until the summer. By then, MnDOT might have a new vendor for all of its transponders.MnDOT has issued a request for proposal for new transponders.

If a new vendor is selected, it's not clear how that might affect holders of transponders currently in use.