Since we've traveled to Port Townsend several times in the last three years, we've driven the stretch along Hood Canal - other than the proximity of campgrounds I wouldn't take it over the peninsula route - way more traffic (and fast) and so-so shoulders. Certainly scenic enough.
Count me in the camp that favors riding the Peninsula and taking in the side trips, if you can. The part that does rub me the wrong way is the lack of HB camping sites at both Kalaloch and Hoh (not to mention a lack of showers). Sure would like to see ACA put some pressure on the Park Service on this. Riding 18 miles one way from 101 to the Hoh to not find a camping spot is not acceptable.
Santa Rosa, CA
Addendum: see this for trail status http://www.olympicdiscoverytrail.com/planning_info/trail_status.html
Of note from that page is this:
Hwy 112 and Lake Crescent to Cooper Ranch Rd
Work is continuing along the Waterline Route, which will connect from Hwy 112, via Gossett Rd, to the East Beach trailhead on Lake Crescent. Current effort is on opening the section of old RR grade from the south end of Gossett Rd to the Waterline Road. When completed this will become the ODT route, replacing the temporary Joyce-Piedmont Rd. route. (posted July, 2015)
The Spruce RR segment construction is now complete from East Beach Trailhead to the old RR grade, except for paving. Paving will be the final step when all construction is complete, about 2018-19. The trail is open now, and users can connect through to SolDuc Rd and beyond using the old (rough) single track path through the tunnel area. This section will be closed summer 2016 for construction through the first tunnel. Specific closure dates will be posted here when available. (posted Jan 2016)
The 2 mile connecting segment, from the Hwy 101 crossing west of SolDuc Rd to the SolDuc bridge, has completed design and should be in construction summer 2016. In the meantime, use the shoulders of Hwy 101 and the 2918 Rd to connect between existing trail segments.
The trail from the 2918 Road (Sol Duc Bridge) to Cooper Ranch Rd Trailhead will be subject to temporary closures between May 12 and about Sept 1 2016, due to selective logging adjacent to the trail and some hauling on the shared (wide) section of the trail. Closures will be posted at both ends of this section and trail users can detour by using the shoulders of Hwy 101 between the FS 2918 road and Cooper Ranch Rd. There will be no closures on weekends or Federal holidays. (Posted May 2016)
Major construction work has been announced for Hwy 101 along the south shore of Lake Crescent for 2017 and 2018. We do not expect any significant widening but the shoulder paving should be repaired. There will be periods of closure of Hwy 101 with traffic rerouted to Hwy 112. These may coincide with closure of the trail on the north shore as part of the tunnel reconstruction, in which case the bike alternate will have to be Hwy 112 (there is no other way through). Closure dates for both will be posted here as they are announced. (posted May 2015)