A study out of DePaul University's Chaddick Institute for Metropolitan Development found that few cyclists obeyed traffic control devices when no traffic was present, and went on to recommended an evaluation of the potential for legally permitting Idaho Stops at intersections with four-way stops, and assessing incremental strategies for allowing Idaho Stops at signaled intersections.
This is not a direct study of the Idaho Stop but rather of current cyclist behavior in parts of Chicago. One of the main conclusions is that when cross traffic is not present few cyclists obey traffic control devices, but that nearly half obey the Idaho Stop at stop signs and 95% either obey the law or the Idaho Stop at stop lights.
At stop signs, just two percent (about one cyclist out of every 50) came to a full stop when cross-traffic was not present while far more (43%) made Idaho Stops, slowing down enough to yield if necessary (Figure 3). The remaining 55% failed to take either precaution. One can posit that when cyclists sense there are no immediate safety risks, their desire to maintain forward momentum and conserve energy almost always exceeds their desire to strictly adhere to traffic laws.
At traffic signal intersections when cross traffic is not present, 30% made full stops and waited until the light turned green, or made a right turn when permitted after stopping. More than twice as many (65%), however, made Idaho Stops, often by proceeding through the intersection before the light changed. Only five percent failed to do either, proceeding through the intersection without stopping or yielding at all.
These results show that in quiet conditions, compliance with traffic laws is far greater at traffic signals than stop signs.
When cross-traffic was present, compliance went up significantly
And compliance appears to be higher at peak traffic hours (54%) than at off-peak (44%).
The study then references previous studies [Meggs (2010), Leth, Frey, & Brezina (2014) etc...] showing that the Idaho Stop may be safer or, at least, no less safe than the current law; as well as studies showing that full compliance on city streets results in ~40% reduction in average speed.
Based on this, the report makes the argument that with compliance so low - especially at stop signs - enforcement "would seem arbitrary and capacious" and that "permitting Idaho Stops at stop sign intersections would help bikers feel more confident that enforcement efforts are being directed toward cyclists who pose legitimate safety risks, and may help to bolster confidence that the law enforcement community is more wisely allocating its limited resources."
They also recommend allowing the Idaho Stop at stop lights either as a pilot at select low-volume lights, or at low volume times like 11pm-5am.
Although such measures would require further study prior to implementation, it behooves the city to gradually move toward rules that reflect reasonable tradeoffs between convenience and safety. The City could also make known that law enforcement personnel will avoid issuing citations for Idaho Stops as a precursor to possibly legalizing them.
The same study also compared travel times, finding that neighborhood-to-neighborhood trips, as opposed to those more likely to be performed by commuters such as downtown-to-neighborhood, or outer downtown-to-neighborhood, were the trips where cycling is the most competitive, being faster than both transit or UberPool.
The Chicago Tribune reported on it, including opinions of local leaders and the study authors on the idea of the Idaho Stop.
"It's tough to step up enforcement without aligning the rules with reality," said study co-author Joseph Schwieterman.
Jim Merrell, of the Active Transportation Alliance, said the advocacy group favors updating policies to keep people safe and to "reflect the way people are actually moving around the city, and that includes the Idaho stop." He noted that the Idaho stop is about yielding and slowing down, not about blowing through a stop sign without paying attention.
The Chicago Department of Transportation has not favored the Idaho stop to date, but spokesman Mike Claffey said the department would review the study and see how the proposal would balance the safety of all users while also encouraging bicycling.
["Bicycling Ambassadors" program manager Charlie Short] could not comment on the Idaho stop idea but noted that sometimes bicyclists make choices they think make them safer but can lead to other dangers. He said some cyclists and motorists don't know the rules of the road, others don't care and some are just doing what everyone else is doing. Short said education discourages unsafe behavior, which drops on corners where outreach events are held.
The study also recommends lower fines for cyclists. In Chicago they can be as high as $200, but in DC they're capped at $25. Though they're higher in Maryland and Virginia.