Any rational proposal to reduce drunken driving on Hawaii’s roadways deserves careful consideration. That includes House Bill 306, which proposes another tool against repeat intoxicated drivers — an ankle bracelet that detects when they’ve consumed alcohol.

Many jurisdictions across the country use the tool, known as a continuous alcohol monitoring (CAM) device, which detects the presence of alcohol in the sweat of the wearer. Proponents of CAM devices tout them as effective deterrents to recidivism. The actress Lindsay Lohan wore them.

Nonetheless, HB 306, for all its laudable intentions, suffers from flaws that need to be addressed before bringing CAM devices to Hawaii law enforcement.

Many of those flaws were pointed out by those opposed to HB 306, including the Public Defenders Office, Mothers Against Drunk Driving HAWAII, and the state Department of Transportation.

Abstinence from alcohol as a condition of bail, and use of a CAM device to monitor compliance, would be mandatory for those charged with DUI, if they have prior convictions or other pending DUI charges. This differs from a device already in use in Hawaii — the ignition interlock, which prevents a drinking driver from starting his car. The interlock is not mandatory for those charged or convicted of DUI, unless they want a license to drive.

It’s an important difference. The accused, faced with a mandatory CAM device and a non-mandatory interlock, would be motivated to skip the latter.

Why? To save money, for one thing. Like the interlock, the cost of the CAM device would be borne by the accused. Compared to the $3 per day interlock, the CAM device is pretty pricey: estimated at about $12 to $15 a day. It will add up: The bill would require abstinence from alcohol for a minimum of 90 days.

This raises the question of cost, and equal access to justice. An indigent defendant — who, it should be noted, is only charged, not convicted — may be unable to afford the mandatory device. The bill contains only vague provisions requiring the vendor to partially cover the costs. Meanwhile, the defendant could end up sitting in jail until he can prove he is poor enough to qualify for relief. A well-off defendant could simply write a check and be on his way.

Unlike the interlock, the CAM device does not prevent a repeat offender from starting and driving his car after drinking. That could lead to tragedy. Common sense says that a fair number of these repeat offenders already have a problem with alcohol, and won’t be able to stay on the wagon for 90 days without assistance.

Dealing with CAM violations, including the required hearings on increasing or revoking bail, could prove costly and burdensome on the court and jail systems. It’s also not clear from the legislation how the system will be monitored and enforced.

None of this is to say that CAM devices are more trouble than they’re worth. Of the 93 traffic fatality deaths in 2015, 51 of them were linked to alcohol and/or drugs, according to the state Department of Transportation. In the same year, the Administrative Driver’s License Revocation Office adjudicated 1,071 repeat offenders — 17 percent of the total number arrested for DUI.

If CAM devices can reduce those numbers, it’s all to the good.

But lawmakers will need to address the practical consequences of such a mandatory program. One way would be to require a person wearing a CAM device to get alcohol abuse treatment at the same time, to reduce the possibility of violations. Another would be to establish funding to make it less burdensome on the poor. Any CAM program should work in concert with the ignition interlock program, which has proven effective in stopping thousands of potential drunken driving incidents.

Repeat DUI offenders pose a serious threat to all Hawaii residents. Let’s get them off the road — and if possible, off the sauce, with the help of CAM devices.