Northbound I-405 Lowering - June 2006
| Length of section to be lowered |
920 feet |
| Width of section to be lowered |
55 feet |
| Area of section to be lowered |
50,600 square feet |
| Depth of lowering |
Up to 3 feet |
| Thickness of existing pavement that we'll remove |
11 inches |
| Thickness of material under the pavement that we'll remove |
Varies from 2 to 23 inches |
| Volume of existing pavement and other material that we'll remove |
6,235 tons or 390 truckloads |
| Depth of material and pavement that we'll replace |
12.6 inches |
| Volume of pavement and other material that we'll replace |
3,480 tons or 217 truckloads |
| Length of lane and edge lines to paint |
4,600 feet |
| Number of construction contractors working on the freeway lowering |
6 (1 prime + 5 subs) |
| Number of workers working on the freeway lowering at any one time |
About 20 |
Traffic Data
Average number of vehicles using northbound I-405 at NE 124th Street
| Per day on a typical weekday |
150,000 |
| Per hour on a typical Saturday midday |
4,200 |
| Per hour on a typical Monday evening rush hour |
5,500 |
| Maximum number of vehicles per hour on the bypass during construction |
3,000 |
Average number of vehicles using NE 124th Street over I-405
| Per day on a weekday |
43,000 |
| Per day on a Saturday |
37,000 |
| Per day on a Sunday |
32,000 |
| Per hour on a typical Monday evening rush hour |
3,100 |
| Per hour on a typical Saturday midday |
2,900 |
| Per hour on a typical Sunday midday |
2,600 |
Lane closures
| Total number of northbound I-405 lanes at NE 124th St. |
4 (3 general-purpose and 1 HOV) |
| Northbound lanes closed during construction |
4 |
| Northbound lanes on temporary bypass |
2 |
| Width of lanes on bypass |
11 feet (plus 1-foot shoulders) |
| Number of hours northbound mainline is scheduled to be closed |
79 |
| Total number of southbound I-405 lanes through Kirkland |
4 (3 general-purpose and 1 HOV) |
| Southbound I-405 lanes closed during construction |
0 to 1 |
Ramp closures
| Number of ramps at NE 124th interchange |
8 |
| Ramps at NE 124th closed during construction |
1 |
Information and assistance for I-405 users
| Number of members on our e-mail update lists to whom we're sending information on this closure |
About 7,000 |
| Number of portable electronic freeway signs we’re using to provide driver information |
8 |
| Number of King County Metro bus routes affected by the closure |
8 |
| Number of Sound Transit bus routes affected by the closure |
3 |
| Number of Community Transit bus routes affected by the closure |
2 |
| Number of extra incident response patrols we’re adding in the project area during this construction work |
2 |
| Hours of incident response coverage per day during this construction work |
16 |
| Normal hours of incident response coverage per day |
10 |