Ada County Highway District

ACHD's Road Wizard Sunday, February 21, 2016 ACHD's Road Wizard

Speed limit increase on Orchard Street south of Overland Road explained; ACHD's role in the Syringa Valley development proposed for South Boise -- who pays for the new roads?

The Road Wizard Replies

Dear Road Wizard: I'm writing to find out why the speed limit on Orchard Street south of Overland Road was raised from 30 mph to 35 mph. Just up the hill two blocks is a crosswalk and an elementary school zone. Even outside of school hours children walk along Orchard and cross to use the playground. There are several houses with driveways that enter directly onto Orchard. Raising the speed limit does not follow the normal speed limits set around the Treasure Valley for these circumstances. What engineering or traffic investigation was done prior to this change? Was public input taken? How was this decision made?

Road Wizard:

A citizen asked for a 35 mph speed limit to be posted for the entire length of four-lane Orchard. When these types of requests come in, ACHD does a speed study. The same is true for when people ask for speed limit decreases.

ACHD observed driving speeds and collected crash data, and considered Boise Police Department input. It was determined that going to a 35 mph speed limit on two sections of Orchard was appropriate.

The stretch of Orchard south of Overland to Targee Street (near the school) was one of them. It had the lowest crash rate of any portion of the five-mile Orchard corridor. That's despite the fact that only three percent of drivers were found to be traveling the 30 mph speed limit. The average speed was 37 mph.

The new posting may cause some people to go a little faster, but ACHD rarely sees a significant change in actual speeds when a speed limit is adjusted. For this part of Orchard, the 35 mph speed limit is expected to put most drivers into the obeying-the-speed-limit category. This allows police officers to direct their resources toward catching truly dangerous speeders.

As for the safety of children, the part of Orchard south of Overland has flashing yellow beacons to go along with the 20 mph school zone, plus new sidewalks. There is also a signalized pedestrian crossing. ACHD will consider all of that during a follow-up study to see how people are responding to the new speed limit.

Dear Road Wizard: With the extension of Lake Hazel Road, there has been a proposal for a Goliath-sized subdivision that will have a huge potential impact on traffic in the area. Does ACHD have a say on approving a subdivision based on road capacity? (During rush hour, it is hard to imagine Cole Road handling much more.) If improvements are made to the roads in this situation, who pays for it? Taxpayers or developers?

Road Wizard:

This is the area where the Syringa Valley mega-development is planned. The city of Boise makes the ultimate decision on whether the 2000-home, Harris Ranch-style community is right for the city. But ACHD reviews traffic impacts before developments can be approved.

For Syringa Valley, ACHD determined in January that no more than 170 homes could be constructed unless Lake Hazel is extended even farther to connect to Orchard Street south of Interstate 84. The extension would lessen traffic impacts on existing streets like Cole.

The road project would be funded in large part by impact fees, which is basically a government charge on new development. The fees require developers to pay their share of improvements needed as a result of new developments.

Return to Road Wizard

Have a Question for the Wizard?

E-mail it to:

Or mail it to:
Road Wizard
3775 Adams St.
Garden City, ID 83714

You may include photos of a particular situation, but photos cannot be returned.

Road Wizard Archives

Additional years are also available by request.


We Drive Quality Transportation For All Ada County ~

Ada County Highway District © 2017
For Questions or problems with this Web site contact the Webmaster