Whanganui's war on speed got the wobbles when a district council committee charged with finalising a draft bylaw unexpectedly adjourned its meeting on Tuesday.
The proposed bylaw recommends a raft of speed reductions for several city and rural roads.
Six of the 13 councillors at yesterday's statutory management committee opted for a rest stop as confusion over possible illegalities and questions around new national guidelines arose.
Councillor David Bennett said submissions from former state highway manager Errol Christiansen and from the Automobile Association raised concerns that he and several other councillors wanted addressed.
Alan Taylor warned: "I think we are in trouble here - we are being told the new speed limits may be challengeable and unenforceable."
Council officers disagreed saying council was legally safe to change speed restrictions.
After a deadlocked vote whether to proceed the meeting was adjourned. Discussion will resume next month after councillors and officers have had a chance to make inquiries and carry out more research.
One proposal not likely to be in the new bylaw is the reduction of the speed limit in the central business district - from 50km/h to 30km/h.
The proposal came from a submission by Mainstreet but was not part of the original consultation document and therefore cannot be progressed without starting the process over, or amending the new bylaw later on, Mr McDouall told the committee.
Mainstreet chairman Peter Robinson submitted the current 50km/h speed limit was no longer fit for purpose and went back to the days of the Avenue being the main thoroughfare.
"It is no longer a truck and car highway - it is very much a mixed precinct," he told councillors at an earlier meeting.
Another proposal, to increase the speed limit along Heads Rd to 60km/h from 50km/h, also looks doubtful. Officers are now recommending no change to the speed limit after submissions raised concerns about safety at rail crossings, among other reasons.
Proposed changes include:
• Whanganui River Rd (100km/h to 80km/h) and near Ranana township (100km/h to 50km/h).
• Mowhanau Beach (100km/h to 30km/h)
• Mowhanau intersection (100km/h to 60km/h)
• Mosston Rd and Montgomery Rd (various changes from 70km/h to 60km/h and 70km/h to 50km/h)
• Westmere School zone (variable speed zone)
• Heads Rd (remains at 50km/h)
• Rural roads including Blueskin, Kaikokopu, Tayforth, Francis, Wikitoria, Landguard and Airport, Rapanui and Papaiti (100km/h to 80km/h)
More details of the proposed changes available on the Whanganui District Council website.