Lake Tahoe transit: How cellphone data is being used to understand needs

LAKE TAHOE — Despite a regional population of only 55,000 full-time residents, about 10 million vehicles make the trip to the Lake Tahoe Basin per year, according to the Tahoe Regional Planning Agency’s draft regional transportation plan.

It also says that the average number of people in the Lake Tahoe region on a given day is four times the permanent resident population.

The 140-page “Linking Tahoe” draft transportation plan does more than quantify the region’s traffic problems — it also analyzes how people are getting around, what they’re doing and where they’re going — by using cellphone data.

“For transit, it gives us a better idea of where we need to be focusing our efforts,” Tahoe Transportation District Manager Carl Hasty told the Sierra Sun recently.

He said that the cellphone data obtained by the district doesn’t include any personal information, and that the technology has been used by businesses for a long time — although this is a first for local transportation planners at TTD and TRPA.

“In the past, you’d set up cameras to photograph license plates, but you wouldn’t know anything about the person or where they were going,” he said.

Hasty said the district, which has been working with TRPA on the draft Linking Tahoe plan, contacted a vendor who has contracts with cellphone providers.

“You can’t just purchase data,” he said. “You have to come up with a series of questions that you want that data to answer.”

The questions the district wanted answered were: Where people are coming from; which airports they fly into; what roads they are using to travel to Lake Tahoe; whether they are residents, commuters or visitors; and finally, where they were going once they arrived?

In addition to confirming some of the things that planners already knew, the draft plan — which transit officials began working on in the spring of 2015 — also revealed other issues, such as parking.

“We all know parking’s an issue, but when you start comparing it to parking spaces, you realize the number of parking spaces available to us is abysmal and they’re not in the recreational areas,” Hasty said.

Though federal law requires its creation, the regional transportation plan also highlights a number of findings establishing the area’s need for a number of transit improvements.

For example, form the north shore’s state line traveling east into Nevada, about 4.5 million vehicles travel through the State Route National Scenic Byway annually. The 1,283 parking spaces here, according to the plan, create a 3,736-to-1 visitor-to-parking ratio.

Along California Route 89 corridor on the east shore — the stretch of highway from the Placer/El Dorado County line near Tahoma to South Lake Tahoe — reportedly has an 836-to-1 visitor-to-parking spot ratio, despite the fact that it has 1.7 million visitors per year.

Further north, along the corridor from Sugar Pine Point on CR 89 to the California/Nevada state line on Highway 28, there is a 6,441-to-1 visitor-to-parking spot ratio.

In other words, there are about 6.7 million vehicles that travel through this stretch of highways 89 and 28 annually — yet it only has 450 public parking spaces.

Vehicle miles traveled within the basin are actually down, and have been slowly declining over the last decade, according to the plan. However, the population of the surrounding metropolitan areas is expected to continue to increase — to the tune of 4 million people by 2035.

The plan also says that because the region’s main roads run along the perimeter of the lake, they cannot be expanded to meet the growing traffic demands.

“If we’re ever going to be successful in getting people to use transit and reduce vehicle trips, we need to address parking,” Hasty said.